feat: quick settings tile subtitle timer

[l-spiecker]

The current subtitle is a little bit redundant. Would be nice to have nothing there, if clocked out. If clocked in, it could show the current worked or flexi time.

Similar References:

• Caffeine tile of Lineage
• https://play.google.com/store/apps/details?id=moe.zhs.caffeine

Further ideas:

• Switching between worked or flexi time could be a preference or by long pressing the tile.

[mathisdt]

I already tried to display something more meaningful when I built the tile some time ago, but the tile wouldn't update reliably. So I figured it would be better to display no time at all than a (probably) wrong one.

But if someone could make this work reliably, I'd be glad!