types: drop the proto builders

Remove the Proto() methods and RegisterMethodToV1Enum; the v1 API builds
responses from the state views directly now.

hscontrol/db/preauth_keys_test.go

@@ -96,7 +96,7 @@ func TestPreAuthKeyACLTags(t *testing.T) {
 				require.NoError(t, err)
 				require.Len(t, listedPaks, 1)
 
-				gotTags := listedPaks[0].Proto().GetAclTags()
+				gotTags := listedPaks[0].Tags
 				slices.Sort(gotTags)
 				assert.Equal(t, expectedTags, gotTags)
 			},