Initial Spaces, Bugfixes

* Button to browser chat "space", offer to browse a space from the "new
contact" dialog if a space address is entered
* Allow selecting text in command UI notes
* Improve channel reconnection logic
* Do not clear message box after upload
* Don't set empty nickname on bookmarks
* Show missed calls from when you were offline
* Allow searching for emoji to react with (including custom emoji)
* Speed up experimental export
* Do not default to a server-specified invalid option in Command UI
* Prevent audio device selectoin feedback loop on some devices
* Always set up the drawer
* Allow scannning Snikket invites to work for new account

Artifacts