e2e: remove framework package and move shared interfaces into infra

Remove the largely redundant framework package and abstraction. At the moment this just calls through to the infra interface and provides getters and setters for things that can be simply initialised in the BeforeSuite.

A few semantic changes to the infra interfaces too:

• GOBHost() string and GitLabHost() string added to return the domains in use.
• ConfigureCluster(*schedulerv1alpha1.Cluster) error takes an existing cluster and configures it for the infra provider, rather than load a yaml file within the provider implementation.
• Simplify infra methods by removing the passing of test identifier to each method.

Moving to suite-level variables removes repetitive boilerplate from the start of each Describe block.

Longer term we should aim to remove the global envVars state in favour of a typed configuration that each provider can own.

Closes #2102 (closed)