Issue 192 implement new publisher viewer layout designs

[jackshen]

192

• Implemented new Figma designs for Publisher and Viewer layout.
• Split up and componentized the app file for both Publisher and Viewer:
  • InfoBar: this has the indicators, company name, timer
  • *VideoTiles: the actual video content
  • ActionBar: publisher app only, has the share, add source, and start/stop buttons
• Common logic in both Publisher and Viewer to ask user if they want to close tab/nav elsewhere moved to libs hook as usePageClosePrompt.
• File selection modal moved to libs component.
• Bumped patch version to 2.1.0

N.B. most of the changes are not new code, it is just a reorganisation