Display color picker when editing colors

### Godot version

v4.3.dev5.official [c9c17d6ca]

### VS Code version

1.88.0

### Godot Tools VS Code extension version

2.0.0

### System information

Fedora Linux 39 (KDE Plasma)

### Problem statement

It's extremely inconvenient to edit colors manually, and currently the best way to do so seems to be to switch back to Godot every time and find/create a node with a color dialog, or export every color.

### Proposed solution

Add/support a simple color picker for Godot's Color format.