Enhance share fragment

[tobiasKaminsky]

Fix nextcloud/server#15752

This is an overview how I plan to enhance share experience.
UI/UX is inspiried by sidebar of web.

• combine ShareFileFragment with FileDetailSharingFragment: Combined ShareActivity with FileDetailSharingFragment as much as possible #6327
  • reduces work
  • streamline UI/UX
• Add "multiple share links"
• edit labels for share links (Edit label for public share links server#21593)
• split up OCShare and derive PublicShare, EmailShare etc. from it.This will then make it very clean how to react on it UI wise, e.g. currently we have a PublicShare and EmailShare which both can hide download, but EmailShare is bound to ShareeAdapter and PublicShare has its own Adapter.
• compare options / UI of shared links
  • test read only / "allow upload and edit" both for file / folder
• check Public Share folder with editing permission without option to upload files #6412
• remove public link (String) from ocFile, as we now have multiple ones
• think about having sharedViaLink/sharedWithSharee as dynamic value (e.g. when creating OFile object)
• move FileDetailSharingFragment to ViewBindings
• have same sort order as on web UI
• email/link shares on top
• sort by created time
• add video verification
• add many sharees / links
  -> list goes beyond bottom
  -> scrolling not possible
• share password: looks like it has two cursors?
• avatar colors are not in line with server
• right align copy share link button, with enough space
• clarify "no data shared with users yet" -> if not shared to anyone, do not show anything
• change search query to "Name, federated cloud ID or email address…"
• write tests for everything
• write test for hide FAB on sharing view #6715
• note that share option can differ if it is a file or a folder, UI, unit tests, …
• also add notes to receiving share, etc

As this is somehow a big change, I will try to do this step by step.

[tobiasKaminsky]

I will continue with rest of this list once #6327 is in.