Add support for glyph decorations/markers

[mattpap]

Early work in progress. Glyph decorations were added previously, but only in a very limited and experimental fashion. This PR's goal is to improve upon that and establish decorations as a feature and add it to all relevant glyphs. The specific applications of this feature are directed graphs and vector fields.

Example showing Arc, Ray, MultiLine and Bezier glyphs:

fixes #8129

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (6560e98) 92.54% compared to head (aa9c5d4) 92.54%.
Report is 1 commits behind head on branch-3.4.

Additional details and impacted files

@@             Coverage Diff             @@
##           branch-3.4   #13619   +/-   ##
===========================================
  Coverage       92.54%   92.54%           
===========================================
  Files             323      323           
  Lines           20493    20493           
===========================================
  Hits            18965    18965           
  Misses           1528     1528