BUG/TST: added TypeError if object dtypes are detected in dataframe

[sharkipelago]

• closes BUG: round not functioning as expected #55114
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

This PR addresses concern 1 of #55114 - Having consistent behavior with Series.round & DataFrame.round.

A TypeError is raised in a similar way to #61206.

I deleted test_round_mixed_type as I felt that test conflicted with the current intended behavior of DataFrame.round, but a little worried that might break some things, so any feedback is appreciated.

[sharkipelago]

The second concern of the issue was round() did not work for Series or Dataframe when using decimal.Decimal from python's default decimal module. It seems like this is because both NumPy and pandas give array-like structures of decimal.Decimal objects a dtype of object. When I tested NumPy it raised an error on np.array([decimal.Decimal("1.2234242333234")]).round().

If the it the behavior of round() working with Series and DataFrames withdecimal.Decimal objects is still wanted, I thought a clean solution would be to make a new custom dtype for decimal.Decimal. However, that seemed like a pretty big change so wanted to check if there was another way I should be thinking about this bugfix.