Vector layers

[mrtripie]

Text tool is based on @Variable-ind's variation of the tool here: #589 (comment)

• Currently experimental
• Plan is to have a text tool implemented for the first version, new shapes and tools to edit them can be added later

TODO:

• Add translation data

[OverloadedOrama]

An idea I had that could simplify vector layers a lot was to wait for Godot 4.2 and use Image.load_svg_from_string(). We could store all vector data in SVG format inside the vector cels, then compose a string and draw the vector shapes using that method. This should work well, although I can see two potential issues:

• We will still need to handle text differently, as Godot can't load svg images that have text, unless they're being rendered as paths.
• We would need to re-generate the entire SVG string every time a vector shape changes, which could potentially be slow for large images or for cels that contain a lot of vector data.