Move scripts to drevops/vortex-tooling package.

[AlexSkrypnyk]

1. Move scripts/drevops to drevops/vortex-tooling package.
2. Refactor scripts to support loading from a local file (if it exists) using

b=$(basename $0) && export g="_g_${b/[^a-zA-Z0-9_-]/}" && [ -z "${!g-}" ] && export "${g}"=set && [ -x "./scripts/custom/$(basename "$0")" ] && . "./scripts/custom/$(basename "$0")" "$@" && exit $?

3. Move bats unit tests.
4. Move to PHPUnit for workflow tests.

[AlexSkrypnyk]

Community was consulted on this using different channels and there was an equal split of opinions:

1. Scripts should stay with the project because dealing with "magic" coming from a package is not fun.

VS

2. Scripts should be in the package because it is easier to manage everything centrally. When local changes required - they can be patched.

So still not clear what the direction should be. May need further discussions.

Going to leave scripts with the project for now.

[AlexSkrypnyk]

There is a 3rd option: use a package but allow local overrides transparently:
if the custom script with the same name exists in pre-defined custom location (e.g., scripts/custom) - then a custom script will be used, including exit code.

This is the code that works, it's compact, it handles exit code and it has a per-file guard for recursion.

b=$(basename $0) && export g="_g_${b/[^a-zA-Z0-9_-]/}" && [ -z "${!g-}" ] && export "${g}"=set && [ -x "./scripts/custom/$(basename "$0")" ] && . "./scripts/custom/$(basename "$0")" "$@" && exit $?