Controller Manager recovery from invalid URDF errors

[VitezGabriela]

Goal:

Update the Controller Manager to handle errors when the ResourceManager fails to initialize due to an invalid URDF or faulty hardware plugin.

Behavior:

• Catch exceptions caused by parsing invalid URDFs during initialization
• Log error messages
• Reset the resource_manager_ pointer to a minimal, safe state.
• Continue waiting for a valid robot_description to be published

Observations:

The Controller Manager now no longer crashes on invalid URDFs. Instead, it safely recovers by initializing the resource_manager_ pointer to a minimal state, allowing the controller manager to continue operating and respond to future valid robot descriptions.

Testing:
Unit tests were created with multiple invalid URDF scenarios. All tests passed successfully. Testing can be done by executing:
./build/controller_manager/test_controller_manager_with_resource_manager

[mergify]

@VitezGabriela, all pull requests must be targeted towards the master development branch.
Once merged into master, it is possible to backport to jazzy, but it must be in master
to have these changes reflected into new distributions.

[mergify]

This pull request is in conflict. Could you fix it @VitezGabriela?

[bmagyar]

a little bit of documentation about the logic happening here would be nice

[destogl]

@VitezGabriela I think we shouldn't change here the logic. But add this to "else" statement as we might lose handling of limits here.

[VitezGabriela]

@destogl The logic is still preserved this way. Importing the joint limits is handled in the method init_resource_manager which is called in upper lines. Otherwise, if the robot description is not valid (or empty), we shouldn't try to import limits but wait on the description.