Migrate public files to the same Files UI

[skjnldsv]

After #28063 and all the various other items in https://github.com/nextcloud/server/projects/6

TODO

• Folder view
• File drop
• Single file view

Will allow

• ⬆️ Allow chunked public upload #4109
• "File drop only" for internally shared folders #16515
• Direct link to files within folder with share link #3234
• Parameters for public share urls #26536

Needs

• Public dav endpoint v2 #32400

[nooblag]

Great to see this in progress! 👍