* [WEB] add UI for transcription

* add analytics event for button, do not use global APP object

* use props instead of state, use local conference to kick participant

* put imports in alphabetical order

* add translation for TranscribingLabel

* fix merge conflict

* add closed caption button

* purge OverFlowMenuItem which starts and stops Transcription

* readd closed caption icon and fix small issues due to purge

* delete unused icon in _font.scss

- Update font files to add new icon.
- Update markup and style so the icon has a small background
  to fill in the text of the icon.
- Remove some css transitions that don't seem to do much.

* feat(icons): add new recording button icon

* feat(toolbar): show different rec/streaming icon

Due to the difference in nature, the iOS and Android implementations are
completely different:

iOS: MPVolumeView is used, which allows us to place a button which will launch a
native route picker provided by iOS itself. This view is different depending on
the iOS version, with the iOS 11 version being more complete.

Android: A completely custom component is used, which displays a bottom sheet
with the device categories, not devices individually. This is akin to the sheet
in the builtin dialer.