Remove complex fn_actions macros

[fauxpark]

Description

These are the last remnants of the deprecated fn_actions system, apart from the LFKeyboards code which I will tackle in a separate PR.

I tried to migrate as much as I could but unfortunately a lot of this stuff was too complex and probably requires conversion to Tap Dance. I didn't want to spend much more time on it, so some parts have had to be deleted without migration.

@uzytkownik
@nrrkeene
@ccojocar
@nathanejohnson
@jasontwong
@willwm
@technovangelist

@algernon your Ergodox community layout has been completely removed for the above reasons, and it also contains images which we don't want in the repo.

Feel free to submit followup PRs fixing what I've broken :)

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[drashna]

Yes, PLEASE!