Completely replaces vcpkg with CPM for all "system" dependencies. Primarily needed for Android and Windows. Also uses my OpenSSL CI for those two platforms.
In theory, improves configure and build time by a LOT and makes things much easier to manage
Reviewed-on: #250
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Transfers the majority of submodules and large externals to CPM, using source archives rather than full Git clones. Not only does this save massive amounts of clone and configure time, but dependencies are grabbed on-demand rather than being required by default. Additionally, CPM will (generally) automatically search for system dependencies, though certain dependencies have options to control this.
Testing shows gains ranging from 5x to 10x in terms of overall clone/configure time.
Reviewed-on: #143
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
