Add framework for global role integration tests

[JonCrowther]

Summary

This PR adds some initial integration tests to Global Roles. It covers 4 basic create cases

1. Testing that the cluster role gets created and uses generated name
2. Testing that the cluster role gets created and uses given name based on annotation
3. Creating a global role with namespaced rules creates the right roles in the right namespaces
4. Creating a global role with catalog rules (ie the resource template) creates a role in cattle-global-data

To make it as easy as possible to add new tests, I kept the tests very simple. The test is this structure

struct {
	name        string
	globalRole  v3.GlobalRole
	roles       []rbacv1.Role
	clusterRole rbacv1.ClusterRole
}

• name: name of the test
• globalRole: the created global role
• roles: expected roles to be created
• clusterRole: expected cluster role to be created

I also moved some logic to tests/controllers/common/common.go because I envision it being re-used by future integration tests.

Limitations

This PR is meant to introduce the integration test framework. It is not comprehensive coverage of global roles. Some additional tests for future work:

• Testing update functionality
• Testing that roles with the wrong GlobalRoleOwner label get removed
• Any testing of failures/conditions

Another limitation is that envtest doesn't run the controllers that monitor OwnerReferences and do garbage collection. So when a global role is deleted, the cluster roles and roles that are owned by it don't get deleted. I added checks to make sure the OwnerReference of these are set to the global role, which indicates that they would get deleted in a full scale kubernetes system.

Finally, in order to run the tests in parallel, each global role needs a unique name. Otherwise there are collisions and it causes the test to fail. Alternatively, the tests could be run sequentially, but the issue might still happen if the delete takes a long time to occur.

[raulcabello]

It looks great! I left some small comments.
Thanks Jonathan!