Requires qt6-static, obviously... at least for eden. eden-cli also can
be built fully static
Notable challenges n such:
1. VkMemAlloc conflicts with Qt, since it embeds vk_mem_alloc.h in
qrhivulkan; we can get around this by conditionally defining
VMA_IMPLEMENTATION; that is, define it in the SDL2 frontend and undef
it in the Qt frontend. It's not ideal, but I mean... it works, no?
2. find_library, pkgconfig, and some Config modules will always look for
a .dll, so we have to tell CMake to look for .a
3. In spite of this, some will end up using .dll.a (implib) as their
link targets; this is, well, bad, so we create a find_library hook
that rejects dll.a
4. Some libraries have specific configs (boost lol)
5. Some libraries use _static targets (zstd, mbedtls)
6. Some extra libraries need to be linked, i.e. jbig, lzma, etc
7. QuaZip is sad
Needs testing on all platforms, and for both frontends on desktop, to
ensure Vulkan still works as expected.
Signed-off-by: crueter <crueter@eden-emu.dev>