[web] Reintroduce MessageTimestampTooltip in ChatMessageList
Summary:
This diff is the first part in a stack of commits that will work to fix the timestamp bug outlined in this Linear issue. Also see @ashoat's comment on D3567 for more context.
This diff removes the timestamp from MessageTooltip and instead reintroduces MessageTimestampTooltip in ChatMessageList, thus reverting the visual aspect of this change to what the timestamp tooltip used to look like before MessageActionButtons was introduced.
The reason this was done is:
- Start the new stack of diffs to fix the timestamp bug
- By moving the timestamp out of MessageTooltip, the component is no longer inside the messageContainer in ChatMessageList which has a overflow-y: auto property. This overflow-y property was causing the timestamp to be cut off within the ChatMessageList container since it did not allow any elements to extend beyond its perimeter.
- This reverts the code to a familiar place that we have seen before. This diff should be fairly easy to review -- although there are added files, these are mostly just copied over from the old version of the tooltip/timestamp and the front-end changes are identical.
Test Plan:
Tested on Chrome/Safari and looks as expected.
Reviewers: tomek, jacek, atul
Reviewed By: tomek, atul
Subscribers: atul, adrian, ashoat
Differential Revision: https://phab.comm.dev/D4481