Introduces a strategy pattern for the implementation of the various
armature drawing modes. Instead of having to `switch (arm->drawtype)`
(or `if`/`else if`/`else` chains) everywhere, one function is used to
select the appropriate `ArmatureBoneDrawStrategy` subclass.
In the future this class could be expanded even further. Currently there
are still places where there are explict checks for the draw type,
making it cumbersome to add new types. For now I feel it's already a
good enough move forward; future extensions can be done in later PRs.
No functional changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/106232
f645130465