ENH: Add CoW optimization to interpolate

[phofl]

• xref ENH / CoW: Use the "lazy copy" (with Copy-on-Write) optimization in more methods where appropriate #49473 (Replace xxxx with the GitHub issue number)
• 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/vX.X.X.rst file if fixing a bug or adding a new feature.

This covers everything except the fillna branches, I intend to do fillna in a separate pr

[jorisvandenbossche]

Nice!