Story:
A CommandRunner interface was introduced in OCPBUGS-62714 as part of a bugfix. This interface abstracts command execution (exec.Command) to improve testability and flexibility, but it's not complete and it's not consumed as a central API to run exec commands in the MCD due to the bugfix nature of the original PR.

1. Extending it's usages to replace all the calls to exec.Command that are not the ones of runGetOut (that effort is covered by MCO-1924).
2. Update the unit tests to run, if possible, the mocked commands.
3. Remove the runCmdSync free function

Acceptance Criteria:
  - All direct runCmdSync() calls migrated to use CommandRunner interface
  - Global runCmdSync() function removed
  - All affected structs use dependency injection for CommandRunner
  - Existing tests updated and passing
  - New unit tests added for migrated code
  - No regression in functionality