Show edit history of a message

[gnprice]

I.e., this Zulip feature:
https://zulip.com/help/view-a-messages-edit-history
The edit history includes when the topic was renamed or the message was otherwise moved, as well as when the message content was edited.

A related, prerequisite issue is:

• Show edited/moved marker on messages #171

This issue goes beyond that and is a feature zulip-mobile doesn't have. Corresponding issue in zulip-mobile:

• Allow viewing message edit history zulip-mobile#4134