Draft: Experimental GResource Inkscape

Advice from upstream and other Gtk projects is that for speed on windows we should compile resources into the Inkscape binary.

This is a highly experimental version with resources compiled in:

• CMake can build the resources header and source files
• Gtk Builder files
• Icons or Icon themes (resources integrations?)
• Extensions (requires listing resources, we'll add all the shipped inx files as xml)

Any other files? Let me know.

Speed Tests

This test is this MR vs. Master, you can see it's saving 100ms on loading extensions. The UI appears faster too, though not much difference in the speed from these marks in the code. (Linux, so I was expecting this to impact windows the most, but can't test it). Another 10ms can be saved by asking it to not check dependencies for system extensions (assuming they are always correct)