Automatic detection of package names when setting up the CI

[destogl]

    I am not quite sure what's the best way to solve this: If user doesn't provide "first_package second_package ..." this is set to none which later on results in `$PKG_NAME$` not substituted inside some workflows (e.g. [CI-github_ci-ros-lint.yml](https://github.com/StoglRobotics/ros_team_workspace/pull/49/files#diff-2f6c1f68ed390ec52cdc7f2fc2e7b5b5d749ac7dd69a79bcb41aca9bb8fecf42)). This in return results in some workflow failing with a none too obvious error message, at least in my opinion. Either:

• Warn user about this?
• Make at least one package mandatory?
• Automatically detect packages and let user select?

_Originally posted by @mamueluth in https://github.com/StoglRobotics/ros_team_workspace/pull/49#discussion_r979748095_