[21226] Add skip_base input option to get_related_branch_from_repo action

[JesusPoderoso]

Description

The get_releated_branch_from_repo action tries to find a branch with the same reference (name) in the given repo.
If fails, tries to get a branch with the same base name, else the given fallback branch.
We have already experience some issues with this actions, because it is used by eProsima products supported branches in nightly CI (for instance, lets say Fast DDS Gen 2.5.x), and instead of using the fallback of other product (Fast DDS 2.14.x), it finds a base branch in the repo that was not desired to be used (Fast DDS 2.5.x in this case).
This PR allows skipping the base branch step, so if the ref branch is not found, it uses directly the given fallback branch.

Contributor Checklist

• Commit messages follow the company guidelines.
• Changes are API compatible.
• New features have been added to the versions.md and README.md files (if applicable).

Reviewer Checklist

• The title and description correctly express the PR's purpose.
• The Contributor checklist is correctly filled.

[irenebm]

Please, update the action description to include information about the new option.

[irenebm]

LGTM