Integrate avatar probe generator into dynamic probe generator

[mpmxyz]

What is the reason for this feature?
The dynamic probe generator is a modular base that implements different workflows.
Integrating the avatar probe generator into it will avoid code duplication and allows synergies when cross-cutting features are introduced.

Describe the solution you'd like

• There should be a tab for "avatars".
• Within that tab should be a list of recorded avatars. Within that tab is a list of users with the option to add probes for their avatars.
• The local selected user's avatar can be added to the recording:
  • proxies
  • body nodes
• There should be an option to create a duplicate of a user's avatar that can be used for playback. (Note: This is smarter than accessing an unoccupied avatar because it allows iterating the body nodes to create a mapping before duplication. Mapping creation can share code with probe generation OR mapping creation is part of linking to the recording.)
  • The mapping is created implicitly when using the option to give slots unique names. (Create abstraction between Links and Columns #16 will allow modifications after recording.)
  • The user needs an info about manual actions that are required to make the duplicate work. (remove IK/hand poser)
    This can be made simple by telling the user to destroy all components that drive one of the playback slots. (->follow the RED texts)
• There should be documentation.
• Linking the playback is out of scope of this issue because it will be generalized via another one. (Create action that emulates animator component's "setup fields by name" behavior #45)
• Actions to make slot names consistent are out of scope of this issue. (Action to ensure names of source/probe/playback match #46)
• Overrides for automatic renaming are out of scope for this issue. (Dedicated slot naming scheme for avatar's proxies/body nodes #47)

[mpmxyz]

A first draft of probe generation based on body nodes has been implemented.

[mpmxyz]

The avatar probe generator has been fully reimplemented into the probe generator.
It is missing essential documentation of the workflow, though.