Remove unused icons
Remove fill none from icons
Rename some icons

- add possibility to allow execution of the button's routine besides triggering
`toolbarButtonClicked` API event
- keep backwards compatibility
- get rid of `ToolbarButton`

* feat(prejoin) move invite to toolbar section

* feat(premeeting) redesign prejoin and lobby screens

* code review changes

* fix prejoin flicker and avatar id

* fix password error message and native lobby dialog close position

Also enable background selection while muted.

That means all browsers except Safari, for now.

In addition, use the 96p model (instead of the 144p one) on browsers without SIMD support.