[WIP][v1.34.0] More user requests

I'm going back to implementing more user requests.

Changes so far:

• Updated the design of the user profile screen slightly.
• Fixed a bug when viewing information about moderated communities/subscribed communities.
• Added a setting to choose a "quick action" for the post feed floatiing action button (FAB) (button at the bottom). When set, this action will trigger when the FAB is long pressed.
• Improve options menus even further.
• Handle Lemmy links to custom frontends.
• Added setting to show edited times in post/comment headers.
• Fixed a crash when trying to preview an extremely high resolution image.
• Fixed a crash when interacting with spoiler tags.
• Fixed a rare crash.