* Improved execution & tests

* Style

* Made CLI arg const

* Moved Upwards message

* CLI subcommand for validation worker

* Build halting parachain

* Build halting parachain

* Made stuff private

* Reorganized parachain tests

* Comment

* Whitespace

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>

* Fixed call data size check and introduced an enum

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>