As part of the Chat widget, when the [+] button is clicked we should show a window that displays existing public channels (that are populated) as well as allow the user to create/join one.

Provide an input box for channel name and channel password.

Checklist:

1. Handle On Click of [+] button event.
2. Retrieve the list of public channels currently available, with list of participants. (Arbiter server work required).
3. Allow for selecting or typing in the channel, and send the Join Channel request to Arbiter.