* feat(welcome-page): be able to open settings dialog

- Create a getter for getting a settings tab's props so the device
  selection tab can get updated available devices.
- Be able to call a function from a tab after it has mounted. This is
  used for device selection to essentially call enumerateDevices on
  the welcome page so the device selectors are populated.
- Remove event UIEvents.AUDIO_OUTPUT_DEVICE_CHANGED. Instead directly call
  setAudioOutputDeviceId where possible.
- Fix initialization of the audioOutputDeviceId in settings by defaulting
  the audio output device to the one set in settings.

* squash: updateAvailableDevices -> getAvailableDevices, add comment for propsUpdateFunction

* feat(settings): setting dialog

- Move device selection, profile edit, language select, moderator
  options, and server auth into one modal with tabs.
- Remove side panel profile and settings and logic used to update
  them.
- Pipe server auth status into redux to display in the settings
  dialog.
- Change filmstrip only device selection popup to use the new
  stateless settings dialog component.

* squash: do not show profile tab if not guest

* squash: profile button not clickable if no profile to show

* squash: nits

* ref: Settings dialog.