REF: refactor implementation of to_dict out of frame.py and into core.methods.to_dict
- [x] closes #49845 (Replace xxxx with the GitHub issue number)
- [ ] [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
- [x] 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.

Following https://github.com/pandas-dev/pandas/pull/46487#pullrequestreview-1059398661 a decision was made to move the implementation of `to_dict` in `frame.py` into `pandas.core.methods.to_dict`.
@rhshadrach friendly ping Thanks @kostyafarber! There are other methods that should now go in this directory - describe is one example. Would you be interested in continuing this kind of refactor? Hey @rhshadrach no worries, glad I can help - Yeah sure! 

If you wanna open up an issue with a list of methods, I can open PRs against them and work on it.  @rhshadrach shall I look into describe or are you compiling a list? Happy to work on describe in the meantime. @kostyafarber - I don't plan on compiling a list; I think describe would be great to work on. @rhshadrach `describe.py` currently is as a standalone file in `core` would the refactor simply be moving that file into `methods`? ? @kostyafarber - thanks for the ping; yes, that's correct.