Fixes some problems introduced by #49917
* Tree used minimum size as a stretch ratio, so it forced a minimum size of 1.
* Minimum size redone, stretch ratio moved to a separate setting
* Fitting to contents was enforced, this is more intuitive, but in many situations this is undesired.
* Added a clip content option for situations where fit to contents does not apply.
* Icon would scroll with the item, making it invislbe if the item is too long.
* Made icon always appear to the right (or left if RTL is enabled) of the visible item space.
* Fixed and redone the process to obtain render information from a viewport
* Some stats, such as material changes are too difficult to guess on Vulkan, were removed.
* Separated visible and shadow stats, which causes confusion.
* Texture, buffer and general video memory can be queried now.
* Fixed the performance metrics too.
This is already allowed when using cinematic preview, but not
when previewing a Camera3D the usual way.
Many operations from the View menu still work while previewing
a camera, such as switching between debug draw modes and toggling
information panes.
- Locking nodes can now be done by pressing Ctrl + L, and unlocking with
Ctrl + Shift + L.
- Grouping nodes is now done by pressing Ctrl + G, and ungrouping with
Ctrl + Shift + G (similar to Inkscape).
- Toggling the grid is now done by pressing the `#` key
(also similar to Inkscape). This change was needed as Ctrl + G
now groups selected nodes.
Different shortcuts are used for the lock/unlock and group/ungroup
actions, so that the shortcuts are idempotent.
* Removed entirely from RenderingServer.
* Replaced by ImmediateMesh resource.
* ImmediateMesh replaces ImmediateGeometry, but could use more optimization in the future.
* Sprite3D and AnimatedSprite3D work again, ported from Godot 3.x (though a lot of work was needed to adapt them to Godot 4).
* RootMotionView works again.
* Polygon3D editor works again.
* Functions to convert to/from degrees are all gone. Conversion is done by the editor.
* Use PROPERTY_HINT_ANGLE instead of PROPERTY_HINT_RANGE to edit radian angles in degrees.
* Added possibility to add suffixes to range properties, use "min,max[,step][,suffix:<something>]" example "0,100,1,suffix:m"
* In general, can add suffixes for EditorSpinSlider
Not covered by this PR, will have to be addressed by future ones:
* Ability to switch radians/degrees in the inspector for angle properties (if actually wanted).
* Animations previously made will most likely break, need to add a way to make old ones compatible.
* Only added a "px" suffix to 2D position and a "m" one to 3D position, someone needs to go through the rest of the engine and add all remaining suffixes.
* Likely also need to track down usage of EditorSpinSlider outside properties to add suffixes to it too.
* Editor 2D viewport now uses embedded subwindows (windows no longer pop up)
* Restored the ability to disable 3D on the 2D viewport (makes 3D not display on 2D when there is a camera on the scene)
