Save initial signup information for users to aid in spam prevention (#31852)

This will allow instance admins to view signup pattern patterns for
public instances. It is modelled after discourse, mastodon, and
MediaWiki's approaches.

Note: This has privacy implications, but as the above-stated open-source
projects take this approach, especially MediaWiki, which I have no doubt
looked into this thoroughly, it is likely okay for us, too. However, I
would be appreciative of any feedback on how this could be improved.

---------

Co-authored-by: Giteabot <teabot@gitea.io>

services/auth/source/oauth2/source_sync_test.go

@@ -36,7 +36,7 @@ func TestSource(t *testing.T) {
 		Email:       "external@example.com",
 	}
 
-	err := user_model.CreateUser(context.Background(), user, &user_model.CreateUserOverwriteOptions{})
+	err := user_model.CreateUser(context.Background(), user, &user_model.Meta{}, &user_model.CreateUserOverwriteOptions{})
 	assert.NoError(t, err)
 
 	e := &user_model.ExternalLoginUser{