Color change for fully constrained elements

[exegetor]

Per request on discord regarding difficulty identifying location of degrees of freedom:

The idea is that when an elements is fully constrained, it is rendered differently so user can tell it's "locked down" and not a source of any degrees of freedom.

An alternative to color change might be displaying thicker line width.

[hlorus]

This is simply a limitation of the solver. Afaik solvespace itself also doesn't communicate this per element. So maybe there's already a topic on their forum somewhere but i haven't found that yet.

[SiboVG]

@hlorus this appears to be a duplicate of #61, should either one be closed?

[hlorus]

Looks like it's not possible to merge discussions, i'll just lock it then.