Refactor some video demo components into classes, seperate files

[hensmi-amazon]

Issue #: None

Description of changes: I was scrolling through meetingV2.ts and sprained my finger, so figured it would be helpful to break this up. I'm not of the opinion that there is too much in this demo, but do think that in it's current form I wouldn't be super comfortable telling builders to just copy paste it as a start. Its also a bit of a headache if you are just looking to see how one component was integrated.

So as a start this breaks out some video related components into their own classes, and moves them to their own files as well. I can see the same being done for local video/audio configuration, and the chat messages.

Testing:

Smoke tested audio/video send and receive in a 3 attendee call.verified active speaker works. verified correct stats overlays. verified pause, and video preference setting worked as expected.

Can these tested using a demo application? Please provide reproducible step-by-step instructions.
There is no feature here. Regression testing should suffice.

Checklist:

1. Have you successfully run npm run build:release locally?
   y

2. Do you add, modify, or delete public API definitions? If yes, has that been reviewed and approved?
   n

3. Do you change the wire protocol, e.g. the request method? If yes, has that been reviewed and approved?
   n

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.