Message Editing: View edit history

[manuroe]

From riot-web created by jryans: element-hq/element-web#9490

For an edited message, we should add an edit history dialog (probably accessed by the "edited" annotation) which shows all edits of the message.

• SDK: expose an API
• Format events into human readable strings (on a separate thread)(the thread will be useful for displaying diffs anyway)
• display them
• date separators
• handle emotes correctly
• do pagination (on scroll)
• order messages descending
• Make it work in e2e rooms