Draft: Tune queue icon

Closes #48 (closed)

Have to be merged after !319 (merged) !321 (merged)

This MR is a proposal to rework the queue icon status.

• Use a cog glyph instead of a database glyph
• Display the amount of queued jobs up to 9
• Use back yellow when it's paused
• Rework the tooltips
  • I have removed 1 state -> it only displays one of Running/Paused/Stopped
  • Display the number of queued job

Todo:

• Create a solid glyph for the cog / maybe including paused/stopped versions
• Center the number, 9+ is not centred anymore
• I think it would be better to remove the running job from number of jobs in the queue
• I think it would be better to use yellow when it's running and green when it's paused
• Better to rework dot-indicator before merging