[21286] Improve CI workflows in master (backport #216)

[mergify[bot]]

Description

This PR improves the CI workflows, making them as similar as possible to the Fast DDS workflows. It also introduces a braching model refactor, similiar as the performed in Fast DDS repository.

It is on top of (and must be merged after) this PR:

• 203

Note: While backporting this PR, please ensure the following changes:

• Remove nightly jobs
• Update ubuntu-ci.yml, mac-ci.yml and windows-ci.yml files with the proper fallback branches
• Maintain reduced version of the RELEASE_SUPPORT.md (only reference to master links)
• Create mirror job on 1.1.x brach (targetting 1.x)
• Fast CDR 1.0.x requires building on ubuntu-20.04

@Mergifyio backport 2.2.x 1.1.x 1.0.x

Contributor Checklist

• [x] Commit messages follow the project guidelines.
• N/A The code follows the style guidelines of this project.
• N/A Tests that thoroughly check the new feature have been added/Regression tests checking the bug and its fix have been added; the added tests pass locally
• N/A Any new/modified methods have been properly documented using Doxygen.
• N/A Changes are backport compatible: they do NOT break ABI nor change library core behavior.
• N/A Changes are API compatible.
• N/A New feature has been added to the versions.md file (if applicable).
• [x] Applicable backports have been included in the description.

Reviewer Checklist

• [x] The PR has a milestone assigned.
• [x] The title and description correctly express the PR's purpose.
• [x] Check contributor checklist is correct.
• [x] Check CI results: changes do not issue any warning.
• [x] Check CI results: CI pass and failing tests are unrelated with the changes.

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  This is an automatic backport of pull request #216 done by Mergify.