fix: request fullscreen for the whole page

[Antreesy]

☑️ Resolves

• Fix broken toast messages, removes need for reparenting Viewer, e.t.c
• Instead of requesting a fullscreen for App, do it for the document.body (hide header and resize content to make it look the same)

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

🏚️ Before	🏡 After

🚧 Tasks

• Check recording appearance
• Check toast messages everywhere
• Check styles in talk sidebars for mounted elements
• Follow-up: get rid of uiModeStore and mainSelector

🏁 Checklist

• 🌏 Tested with different browsers / clients:
  • Chromium (Chrome / Edge / Opera / Brave)
  • Firefox
  • Safari
  • Talk Desktop
  • Not risky to browser differences / client
• 🖌️ Design was reviewed, approved or inspired by the design team- header should be hidden, and app-content stretched to the whole viewport, so apply custom styles

Signed-off-by: Maksim Sukharev [email protected]

[ShGKme]

Do we need this state now, if it is always body?

[Antreesy]

Set to body, so it's not affecting components now. Want to move a clean-up of that store/state to the follow-up PR, since it's touching too many files
(NewMessage is broken now, if state is undefined)

[Antreesy]

Tests:

Name	Pic	Pic2
nested Popovers and Modals
NcActions
Menus
Public chat	👍🏽
Files sidebar
Public share sidebar	not available?
Password share sidebar
NewMessage tributes
Toasts
Recording