There are some bad assumptions about profile changes in here.
* Remove assumption FIXME's
Profile changes that come from other members will be state event of None.
* Bump SDK version.
- Remove context menu (and fix long press when there are no items).
- Add membership change tests.
- Fix new/old name incorrect ordering.
- Fix message grouping when it comes before/after a state item from the same user.
- Only show reactions picker for items that can be reacted to.