- no background
- more space efficient
- consitent height of rows
- slightly smaller previews
- move Manage button next to filter and Add Nodes button to the bottom

- Enables the dotted grid on the GraphEdit
- Moves the UndoRedoLabel into the StatusBar for now

If the Preview 2D (1) preview is locked, it will now not indicate ports on other nodes as previewed, that aren't actually being previewed.

Makes them smaller if possible and have a consistent size.

Added a minimum 2 pixel dragging (otherwise goes to editing), to avoid unintentional mouse movements blocking the click to edit.

Adds a slight outline and some better content margins

Changes the OptionButton (And SizeOptionButton) a bit:
- better popup background
- Allow Ctrl+Scroll to cycle values

Works on FloatEdit, OptionEdit and ColorButtonEdit.

This should make the margins on the left more consistent.
This also fixes minimum size of items.

Creates a brand new GradientEdit with a more complex popup.

Mostly recreates the old feature-set but has some additions:
- New design for the cursors
- Point offset can be set from a FloatEdit
- The popup allows cylcing through the active cursors
- Gradients with Alpha parts are displayed better
- Ctrl+C and Ctrl+V will copy and paste colors from cursors
- Dragging a color onto a gradient will show a preview cursor
- Dragging a color onto a cursor will preview that color
- The popup can be pinned, making it stay even when something outside is clicked. This allows dragging colors or gradients even into the popup or moving the graph view around.
- The gradient can be copied and pasted with Ctrl+C and Ctrl+V.

Main UI/UX improvements:
- Make it clear how to open the popup (previously something you could only stumble upon)
- Remove the interpolation dropdown from the gradient Edit (only in the popup now) to remove visual clutter.
- Allow editing the offset directly, remove offset label.
- Better display Gradients with transparency.

This minimum size was previously ensured because empty labels were added to all the rows. This messed up a bunch of nodes that have lot's of ports with no settings or labels.

Snapping (activated by pressing CTRL when dragging) now snaps to more useful increments based on the range of possible values of the field.

This is an attempt at fixing the graph not fully loading sometimes.

I had increased the hotzone so much, that the small reroute node wasn't even grabbable anymore.