Automatix

- Feature: Shell completion works now for vars, systems, secrets
- Feature: Shell completion for the script files works now even for deep directory trees

- Fix: Reloading while using steps

- Backport changes from fork
- Adjustments due to backporting
- Refactoring: answer options in command.py
- Python action: Make `SYSTEMS` and `CONST` directly available
- Python action: Path to executed script file available as `SCRIPT_FILE_PATH`
- Python action: Automatix variables are now available as `VARS`, replacing `a_vars` (now deprecated)

- Add fine tuning for required version

- Feature: Add RUNNING_INSIDE_AUTOMATIX as environment variable for shell actions
- Feature: Python debug shell option
- Refactoring Python action
- Python action: Global variables are not persistent through commands any longer. Please use PERSISTENT_VARS.
- Python action: Global imported modules/functions/objects are not available without import any longer (re, quote, ...)
- Python action: Automatix variables are now available as `a_vars`, replacing `vars` which was shadowing the builtin `vars()` function

- Add check for proper screen version for parallel processing
- Fix: explanation URL