BUG: Fix MultiIndex alignment issue in Dataframe-Series binary operat…

[snitish]

…ion in case of different levels

• closes BUG: .mul on multi index columns doesnt work. #61009
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/v3.0.0.rst file if fixing a bug or adding a new feature.

In case of arithmetic operations between a DataFrame with MultiIndex columns and a Series, if the two multiindexes don't have the same levels, the output values are all nan (see example in the original issue).
A similar issue for DataFrame-DataFrame arithmetic operations was fixed in #60538. This PR addresses the bug in the DataFrame-Series case with axis=1 (i.e. aligning DataFrame columns with Series MultiIndex).

The fix itself is simple - we just use

right = other._reindex_indexer(join_index, ridx)

instead of

right = other.reindex(join_index, level=level)

because Series.reindex needs the new MultiIndex to have identical levels to the current index. Instead, we simply use the ridx object that we already have from a previous Index.join call, which does handle partially overlapping levels well.

[mroeschke]

Thanks @snitish