Add a few set and map related lemmas

Todo

• Update changelog

mentioned in merge request iris!697 (merged)

Looks like a useful set of lemmas. I left some comments.

added 1 commit

• e22e4a76 - Add changelog entry and make small tweaks

Compare with previous version

Thanks for the review. I've fixed most of the comments and added entries to the changelog.

marked the checklist item Update changelog as completed

resolved all threads

resolved all threads

Thanks for the MR. Going to merge!

merged

mentioned in commit e3800ea7