TST (string dtype): resolve xfails for frame methods
Removed the interpolate-related changes in favor of https://github.com/pandas-dev/pandas/pull/60637 (that PR is turning it into a TypeError instead of NotImplementedError, which seems better?) @jorisvandenbossche @simonjayhawkins any more feedback on this one? This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. Not actively working on this - let's clear the queue