Add functionality for hiding handles that aren't selected

[MissLavender-LQ]

coming from inkscape there should be a way to have the vertices not show up unless selected
also with complex svg files is hard to read whats going on with everything fully expanded

2024-02-22.19-46-17.mp4

inkscape for comparison

2024-02-22.19-47-55.mp4

the svg file if wanted for testing ^

[MewPurPur]

I can't really account for the insanities other SVG editors do in order to support their high-level features. If this graphic were made using raw code approaches, it would be much smaller and not as littered with handles.

GodSVG is intended for more low-level SVG meddling, not a drop-in replacement for editors like Inkscape. There kind of can't be persistent layers because metadata is against one of the core design principles of the application.

This said, one thing in this issue is actionable: Currently, handles are either all shown or hidden, and we can add an "Only show selected" kind of mode.

[MissLavender-LQ]

This said, one thing in this issue is actionable: Currently, handles are either all shown or hidden, and we can add an "Only show selected" kind of mode.

that would be great

feel free to rename this FeatReq