REF: Stop mixing DTA/TDA into DTI/TDI
part of the #24024 process

along the way fixes+tests `DTA.__eq__(ndarray[object])` bug
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=h1) Report
> Merging [#24476](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/4f1c1dcc3336070b03f5a457616e6ba9e15b0030?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24476/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24476      +/-   ##
==========================================
- Coverage   92.32%   92.32%   -0.01%     
==========================================
  Files         166      166              
  Lines       52298    52359      +61     
==========================================
+ Hits        48285    48339      +54     
- Misses       4013     4020       +7
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.74% <100%> (-0.01%)` | :arrow_down: |
| #single | `43.08% <69.79%> (+0.02%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/datetimelike.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9kYXRldGltZWxpa2UucHk=) | `96.14% <100%> (-1.39%)` | :arrow_down: |
| [pandas/core/indexes/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9kYXRldGltZXMucHk=) | `96.38% <100%> (+0.24%)` | :arrow_up: |
| [pandas/core/arrays/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lcy5weQ==) | `98.23% <100%> (-0.03%)` | :arrow_down: |
| [pandas/core/indexes/timedeltas.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy90aW1lZGVsdGFzLnB5) | `90.65% <100%> (+0.4%)` | :arrow_up: |
| [pandas/core/indexes/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9wZXJpb2QucHk=) | `92.46% <0%> (-0.23%)` | :arrow_down: |
| [pandas/core/arrays/datetimelike.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lbGlrZS5weQ==) | `95.45% <0%> (-0.2%)` | :arrow_down: |
| [pandas/core/indexes/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9pbnRlcnZhbC5weQ==) | `95.26% <0%> (ø)` | :arrow_up: |
| [pandas/core/arrays/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2ludGVydmFsLnB5) | `93.04% <0%> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=footer). Last update [4f1c1dc...11dcef0](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=h1) Report
> Merging [#24476](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/3f836274d654b0438586cd00d5053864b791bf66?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24476/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24476      +/-   ##
==========================================
- Coverage   92.32%   92.31%   -0.01%     
==========================================
  Files         166      166              
  Lines       52328    52379      +51     
==========================================
+ Hits        48310    48354      +44     
- Misses       4018     4025       +7
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.73% <100%> (-0.01%)` | :arrow_down: |
| #single | `43.06% <74.41%> (+0.02%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/datetimelike.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9kYXRldGltZWxpa2UucHk=) | `96.23% <100%> (-1.37%)` | :arrow_down: |
| [pandas/core/indexes/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9kYXRldGltZXMucHk=) | `96.33% <100%> (+0.19%)` | :arrow_up: |
| [pandas/core/arrays/datetimes.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lcy5weQ==) | `98.41% <100%> (-0.02%)` | :arrow_down: |
| [pandas/core/indexes/timedeltas.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy90aW1lZGVsdGFzLnB5) | `90.65% <100%> (+0.4%)` | :arrow_up: |
| [pandas/core/indexes/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9wZXJpb2QucHk=) | `92.46% <0%> (-0.23%)` | :arrow_down: |
| [pandas/core/arrays/datetimelike.py](https://codecov.io/gh/pandas-dev/pandas/pull/24476/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXJyYXlzL2RhdGV0aW1lbGlrZS5weQ==) | `95.47% <0%> (-0.19%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=footer). Last update [3f83627...f6a8951](https://codecov.io/gh/pandas-dev/pandas/pull/24476?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 can you merge master lgtm. @TomAugspurger  Thanks. I'll merge this into #24024.