Support authentication for fetching KiCad data

[SchrodingersGat]

Is your feature request related to a problem? Please describe.

Fetching kicad data only supports remote URLs which do not need auth. Either publicly available files or a public git repo. However support for "private" data (e.g. in a self-hosted gitlab server with authentication restrictions) currently will not work.

Describe the solution you'd like

Options for providing authentication credentials to use when fetching remote KiCad data.

Describe alternatives you've considered

N/A

Additional context

I would like to build a plugin for InvenTree which allows you to view your schematic and PCB files directly against the part data in InvenTree. These files could be stored "off site" (on a different server) which requires login credentials to access.