refactor: remove references to v1alpha1 in provider package

**What**

Remove references to v1alpha1 in provider package where appropriate.

Currently we reference "v1alpha1" resource all over the place in the provider package which amongst other things will make it more work to move to newer versions of the api. Things like "ProviderAccessor" should be defined in the provider package, and anything that needs to be exposed in the API such as `SecretTypeKuadrantAWS` etc.. that are used by the provider package should alias them from the provider package rather than the provider package reading them from there.

Start by tracing the provider package references to the v1alpha1 resource, including ProviderAccessor and exposed names such as SecretTypeKuadrantAWS. Identify which definitions belong in the provider package and which API names should alias them; done means the provider no longer depends on v1alpha1 where inappropriate while the exposed API remains available.

Written by the indexing model from the issue text.