refactor: Group object-related utils under 📁`Util/Objects`

[Zearin]

Redo of PR #3252. (My git-fu is weak, and attempts to rebase and merge went fakakta.)

[Zearin]

Description from #3252 that I forgot to add:

A number files in 📁Util are general-purpose tools for manipulating or working with objects.

They told me they wanted to all move in together and be roomies.

[Zearin]

@uncenter @zachleat : Would you be willing to give this a review?

[Zearin]

@zachleat This PR is a quick-and-easy grouping of a couple of modules. Could someone take a look? CC: @uncenter

[zachleat]

Shipping with 3.0.0-alpha.11

[Zearin]

Thank you! 🙏