BUG: Fix DataFrame.apply for string arg with additional args (#22376)
- [x] closes #22376
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22377?src=pr&el=h1) Report
> :exclamation: No coverage uploaded for pull request base (`master@e7fca91`). [Click here to learn what that means](https://docs.codecov.io/docs/error-reference#section-missing-base-commit).
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/22377/graphs/tree.svg?width=650&src=pr&token=eZ4WkYLtcO&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/22377?src=pr&el=tree)

```diff
@@            Coverage Diff            @@
##             master   #22377   +/-   ##
=========================================
  Coverage          ?   92.05%           
=========================================
  Files             ?      169           
  Lines             ?    50709           
  Branches          ?        0           
=========================================
  Hits              ?    46679           
  Misses            ?     4030           
  Partials          ?        0
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.46% <100%> (?)` | |
| #single | `42.25% <100%> (?)` | |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/22377?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/apply.py](https://codecov.io/gh/pandas-dev/pandas/pull/22377/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYXBwbHkucHk=) | `96.75% <100%> (ø)` | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22377?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/22377?src=pr&el=footer). Last update [e7fca91...48d283a](https://codecov.io/gh/pandas-dev/pandas/pull/22377?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 @jreback I checked and ``GroupBy.apply`` doesn't support string func arguments with positional args or keywords so seems like nothing to test there in this PR, see https://github.com/pandas-dev/pandas/blob/b5d81cfe43eeccfc3641aa9578097f726da9ce9d/pandas/core/groupby/groupby.py#L676 thanks @megabyde 