Allow multiple Pinnipeds to work on same cluster

Yes, this is a huge commit.

The middleware allows you to customize the API groups of all of the
*.pinniped.dev API groups.

Some notes about other small things in this commit:
- We removed the internal/client package in favor of pkg/conciergeclient. The
  two packages do basically the same thing. I don't think we use the former
  anymore.
- We re-enabled cluster-scoped owner assertions in the integration tests.
  This code was added in internal/ownerref. See a0546942 for when this
  assertion was removed.
- Note: the middlware code is in charge of restoring the GV of a request object,
  so we should never need to write mutations that do that.
- We updated the supervisor secret generation to no longer manually set an owner
  reference to the deployment since the middleware code now does this. I think we
  still need some way to make an initial event for the secret generator
  controller, which involves knowing the namespace and the name of the generated
  secret, so I still wired the deployment through. We could use a namespace/name
  tuple here, but I was lazy.

Signed-off-by: Andrew Keesler <akeesler@vmware.com>
Co-authored-by: Ryan Richard <richardry@vmware.com>

pkg/conciergeclient/conciergeclient_test.go

@@ -111,7 +111,16 @@ func TestNew(t *testing.T) {
 				WithEndpoint("https://example.com"),
 				WithAPIGroupSuffix(""),
 			},
-			wantErr: "api group suffix must not be empty",
+			wantErr: "invalid api group suffix: 2 error(s):\n- must contain '.'\n- a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')",
+		},
+		{
+			name: "invalid api group suffix",
+			opts: []Option{
+				WithAuthenticator("jwt", "test-authenticator"),
+				WithEndpoint("https://example.com"),
+				WithAPIGroupSuffix(".starts.with.dot"),
+			},
+			wantErr: "invalid api group suffix: 1 error(s):\n- a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')",
 		},
 		{
 			name: "valid",