Rework UI

[Aldrog]

The current UI has a pretty bad navigation system and it's also not flexible enough.
There's also a need for better adaptation to different screen sizes.

[Aldrog]

The current idea:
Main screen with tabs Games, Channels and Followed (when available).
Tabs implemented as a swithcer on the bottom of the screen for Sailfish, as regular tabs for Ubuntu.
Settings are accessed via push up menu on Sailfish, via bottom edge on Ubuntu.
Every tab has a list of actions (pull down menu on Sailfish, toolbar on Ubuntu).
For Games and Channels the only available action is Search.
For Followed there'll be Show Everything - Only Online switcher action (Only Online by default).
Opening stream/channel/game replaces tabs view with a corresponding page.
Game page has two actions: Follow and Search.
Channel page has only Follow.
Stream page has (just like now) Quality and Follow actions.
Stream page will become more adaptive by moving chat to right side on bigger screens.