Independent label archetype

[Wumpf]

We have a bunch of archetypes that support labels, e.g. point 2d/3d, box 2d/3d. However, not only is that list not exhaustive, but we also don't have a way to just add a floating label - the best way to do that right no is to log a point with zero size and add a label to it.

It's worth considering if the labels shown so far are a fully independent archetype (and ViewSystem internally) that just happens to trigger as well when a point has a label component (the aforementioned archetype would ofc keep their label properties). Note though that we can't fully decouple this for all cases since the placement of a label for anything larger than a box needs to know about the box itself to make a decision.
Need to spend a bit more time thinking about this to design something that fits well together overall.

Related to

• need more label customizations: customizable Label Sizes (e.g. for Box2D labels) #4228
• Support for text/labels in 3D #1640