Provide a `MediaRoute` Compose implementation

[MGaetan89]

As a Pillarbox integrator using Compose, I would like to be able to use the AndroidX MediaRouter library without needing to depend on AppCompat.

Acceptance criteria

• A new library is available to use MediaRouter in Compose.
• It should be not tied to Pillarbox.
• Features available in the original MediaRouter library should also be available on Compose.

[MGaetan89]

This new library can be built on top of the PoC made in #859, currently available in https://github.com/SRGSSR/pillarbox-android-mediarouter-compose.

Steps to turn the PoC into a usable library:

• Set up the repository:
  • Rename the repository into androidx-mediarouter-compose.
  • Add a contribution guide.
  • Configure branch protection.
  • Make the repository public.
• Set up the CI:
  • Create a quality workflow (Lint, Detekt, Unit Tests).
  • Create a release workflow (deploy the lib to GitHub Packages).
• Create a new mediarouter-compose module.
• Move code from the app module to the mediarouter-compose module.
• Change the package name.
• Rename the app module to demo.