Make shift clicking the arrows in FileSystem dock work like in the node tree

[Jummit]

Godot version:
97cc2e5

Issue description:
You can only close / open all folders in the FileSystem dock by alt+left/right, not by shift clicking on the arrow like in the node tree.

Steps to reproduce:
Create some folders and shift click the arrows.

[FeatherAntennae]

I'm actually working on this! #33984

Edit:
The shift-clicking is actually what's going to be replaced everywhere by the alt-clicking, to avoid conflict with the multi-selection using shift-clicks.

I'm also proposing to make the behaviour slightly different, so don't hesitate to participate in the conversation!

[akien-mga]

Fixed by #62666.