[Potential Security] Local-only icons

[OdinVex]

Icons should be hosted locally, only. WUD currently provides links to https://cdn.jsdelivr.net/npm/simple-icons@latest/icons/..., and while I doubt jdselivr.net might ever become some kind of victim (especially for SVG-related vulnerabilities) I'd prefer if icons were local, only (at least of the publicly-available types and such). If copyright is an issue then perhaps an ENV to disable remote referencing and serve up local icons users provide for themselves.

Edit: May have relevance for #337.

[thecoshman]

I think you make a fair point... even if in my head right now, it seems a bit 'paranoid' 😅
I think if #337 is implemented, such that alternate icon sources can be provided, then a flag could be added to suppress the default ones. Perhaps these two can be merged into a single request.