Add edit status functionality

This MR adds the edit status functionality seen in pleroma!3678 (merged) to the frontend.

• Edit status button
• Edit status form
  • Fetching source
• Editing works
  • Editing streams for user's own posts
  • Editing streams new attachment descriptions for user's own posts*
  • Editing streams for others' posts
    • Mastodon Websocket*
    • w/o Mastodon Websocket?**
  • Editing streams new attachment descriptions for others' posts
    • Mastodon Websocket*
    • w/o Mastodon Websocket?**
  • Media attachments and polls are preserved
  • Unless edit is officially posted, media attachment edits should not show in timeline, only in edit status form*
• Warn users about limitations
• View history when status has been edited

* Special thanks to @tusooa

** Fetching status when highlighting it will be fine enough IMO. I'm concerned that I will accidentally cause potential DoS situations if I have it constantly refetching multiple statuses within a timeline from the general API at various short time intervals.