Submarine Editor Transform Tool

[Jade-Harleyy]

This PR adds a rotation & scaling tool to the submarine editor.
Its functions can be toggled with the tickboxes to the right of the "Generate Waypoints" button.

With "Edit Rotation" active, users can drag the widget around to rotate the selected entities about the center of the selection.
With "Edit Scaling" active, users can drag the widget around to scale the selected entities about the center of the selection.

The current rotation and/or scaling offset is visible in a tooltip next to the widget while it is being dragged.

Added content is in the mod provided with the PR.
The tickboxes also require their own art to be done, hence the duplicate styles I have added.

[Regalis11]

Thank you for the contribution! This seems like a really handy addition. The code changes look mostly good, but I spotted a couple of things that could have some negative performance implications and would most likely be easy to optimize.

[Regalis11]

I think there's still an issue with how the behavior of the Hovered callback was modified.

[Regalis11]

This still changes the behavior of the method. Previously Hovered was called if the cursor is on the widget, or if it's being dragged and doesn't require the mouse to be on it to be draggable.

If you want the new widgets to behave in some other way, I think that should be handled in the callbacks or by disabling RequireMouseOn.

[SomeRandomNoobKekeke]

1. If you press esc while the widget is grabbed you won't be able to release it, and if you quit to main menu and enter sub editor again the widget will become ungrabable. Because it's still in Widget.SelectedWidgets? God knows how baro gui works
   So i think you should somehow clear SelectedWidgets on quiting

2. I think it should react to moving camera with wasd / mouse scroll while grabbed. Barotrauma widgets do, so i think it's possible

3. Widget should appear at the angle of rotation of the item and initial scale should be set to the scale of the item. I understand that you work with selections, but make an exception if only one item is selected, this is deceiving, it shows you that item always have 0 rotation and 1 scale whenever you grab it

4. Can numbers in the widget have fixed level of precision?

5. When placing walls by dragging why do you snap them to grid? Placing and rotating them manually doesn't have this limitation

6. When you finish placing a wall by dragging, the wall jumps dramatically ruining your precise positioning