Make sure signal method names are lower case

[workhorsy]

If there is an event method named like _on_Check_MSAA_2X_pressed. Godot won't find it. It will instead look fore the name in lower case. Like _on_check_msaa_2x_pressed. Add a verifier that makes sure the names are the correct format.

[connection signal="pressed" from="MSAAContainer/Check MSAA 2X" to="." method="_on_Check_MSAA_2X_pressed"]

@Method void _on_Check_MSAA_2X_pressed() {
}