API function names in module/theme install/uninstall space should match UI

Problem/Motivation

On meta issue
#2888657: [meta] Less confusing and more consistent wording needed in module/theme add/install/update →
we are updating the UI text for the actions of uploading files for a module/theme, and installing/uninstalling modules/themes.

That work is being done on these three child issues:
#2577407: Action of uploading module/theme files should consistently be called "Add", not "Install" →
📌 [Meta] Use Install/Uninstall consistently for turning modules/themes on/off (not Enable) Active
🐛 Do not use verb "Install" for things other than turning on modules/themes Fixed
Plus this one that is updating URLs:
#2888654: URLs for module/theme actions are inconsistent with UI text →

Once that is finished, we should update the API functions/classes for these actions so they are consistent with the UI terminology. This issue is postponed until all those others are done.

Proposed resolution

TBD.

Note that this will need a BC layer and/or deprecations.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet