TST: Use multiple instances of parametrize instead of product in tests

- All instances `product` being used inside a `@pytest.mark.parametrize` have been converted to separate instances of `@pytest.mark.parametrize`
- Extracted `product` from within tests where it was straightforward
- There are still multiple instances of `product` being used within tests for looping purporses
   - Most of the ones left do not appear to be trivial to extract
   - Some instances we might not want to remove/are clearer as-is
   - Could maybe open an issue for some of the more obvious ones?
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/21602?src=pr&el=h1) Report
> Merging [#21602](https://codecov.io/gh/pandas-dev/pandas/pull/21602?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/7bee353cd69ab846317301fdf614a94fbae50117?src=pr&el=desc) will **not change** coverage.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/21602/graphs/tree.svg?token=eZ4WkYLtcO&width=650&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/21602?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master   #21602   +/-   ##
=======================================
  Coverage    91.9%    91.9%           
=======================================
  Files         153      153           
  Lines       49548    49548           
=======================================
  Hits        45538    45538           
  Misses       4010     4010
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.3% <ø> (ø)` | :arrow_up: |
| #single | `41.78% <ø> (ø)` | :arrow_up: |


------

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