ENH: Include `df.attrs` metadata in `to_csv` output
- [ ] closes #53577
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

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This new functionality writes DataFrame metadata stored in `df.attrs` as header/comment lines at the top of a CSV file.

1. The `to_csv()` method had a `comment` param added to its call, matching the `read_csv()` method signature
2. If this param is set all key/values will be written to the beginning of the CSV file in the following format `[comment][key]:[value]`

Given other discussions around df.attrs #52166 this implementation does not use or depend on `__finalize__` at all. Closing to cleanup my forked branch. Will re-open as a new PR