Touchup Mobile UI

[shetaye]

The mobile UI needs significant touchups before it's ready to be released.

Player:
The video player needs a complete redesign. A new video control popup and fullscreen are needed. Internal hooks ready for Phase 3 time tracking are necessary.

Loading:
Spinners need to be replaced with gray wireframes.

Zero states:
When the backend returns an empty response for a query, a proper zero-state message (Icon with a small piece of text) should be shown.

Error states:
When the backend service returns an error, an error message should be shown.

Tab bar:
The tab bar should be redesigned to look nicer.

(From GitLab)

[shetaye]

Since the mobile app isn't being published in phase 2, this is being moved to phase 3.