[Tracking] Hook API v3

# Obvious improvements/Bug fixes (non-breaking)
- [ ] Understand all correct JSON return values
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/2832
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/2744

# API improvements (breaking)
- [ ] Move the default hooks location
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/2431
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/1779
I interpret this, as proposing to move the hook types from the filename to a parent directory (`on-add_hook.sh` -> `on-add/hook.sh`).

- [ ] Pass structured JSON arguments to hooks
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/3839
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/3840
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/1912

- [ ] [Parse, don't validate](https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/)
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/3851

# Add further hook types (non-breaking)
- [ ] `on-urgency-calc`
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/3214

- [ ] Teach `on-launch`, how to modify TW's command line
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/2281

- [ ] `on-sync`
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/2142
(also see [Open Questions](#open_questions))
- [ ] `on-unblock`
- [ ] https://github.com/GothenburgBitFactory/taskwarrior/issues/1815

# Open Questions
- Task created through recurrence [trigger hooks](https://github.com/GothenburgBitFactory/taskwarrior/issues/1546)
This is obviously useful, but also quite unexpected if the task is, for example, created in a `task list` run

- Task revived by synchronizing do [not trigger hooks](https://github.com/GothenburgBitFactory/taskwarrior/issues/2142)
This would be useful, for a mobile client but could also result in infinite loops via two or more desktop clients.
- A possible [solution via taskchampion](https://github.com/GothenburgBitFactory/taskwarrior/discussions/3235#discussioncomment-7969404)

- Should the hook handling be [factored out into a shared library](https://github.com/GothenburgBitFactory/taskwarrior/issues/3838)?

- Can hooks be separated [into _filters_ and _triggers_](https://github.com/GothenburgBitFactory/taskwarrior/discussions/3235#discussion-6001362)?
This would make it easy to add more hook types, if these were mere triggers.