ENH: Make it possible to change type inplace
- [X] closes #43946
- [ ] tests added / passed
- [ ] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit) for how to run them
- [X] This commits adds the possibility of performing the operation of astype directly in a dataframe using the inplace parameter.
