## Description:
The websocket message handler functions have gotten quite large. This
change extracts them to functions in their own file, and extracts the
`"join"` message acceptance logic into its own function allowing for all
cases to be accounted for when we add error messages in #1447.
## Please complete the following:
- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [ ] I have read and accepted the CLA agreement (only required once).
Scott Anderson