Extract commander from custom executor

👋 Need to merge !1653 (merged) before and then change the target branch to master 👋

What does this MR do?

Move commander interface to helpers/process. This was broken out of !1551 (closed) there are some discussion regarding this in !1551 (comment 209856388) & !1551 (comment 209856394) but those would be addressed in a separate MR. The goal of this MR is to just extract in the interface from 1 package to another.

Why was this MR needed?

Extract Commander interface and the os implementation to the helpers/process package so that we can re-use it to the shell executor.

reference #3376 (closed) reference #4438 (closed)

Are there points in the code the reviewer needs to double check?

👋 When reviewing this merge request take a look at !1551 (closed) 👋

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Added tests for this feature/bug
• In case of conflicts with master - branch was rebased

What are the relevant issue numbers?

• Broken out of !1551 (closed)
• Part of #3376 (closed)
• Part of #4438 (closed)