Themed some voice stuff

[FedeIlLeone]

This PR themes and fixes some little details on voice pages.

Changes made:

• Themed:
  • Stream preview tiles.
  • Invite, Watch Stream and Hide Members buttons in voice channels.
  • Quality and LIVE indicators in voice channels.
  • Stage channels voice controls; sharing the same from the normal voice channels.
  • Tooltips; some do not share the same class.
• Fixed the "Share Your Screen" button on the channels sidebar being the same color when streaming content.
• Fixed the fullscreen mode when in a voice channel. Before, you could still see the servers sidebar.