Editor gizmos improvements: XY movement comfortable for 2D games and 2 important fixe

[DP News-Robot]

We improved behavior of gizmos (for translating, rotating, scaling TCastleTransform in the editor): The translation mode is more comfortable for 2D games. When you have typical 2D projection (orthographic, and camera looks along -Z axis) then clicking on a special box in the middle of the gizmo, or clicking on the Z arrow (previously a …