Rename Handle to HorizonHandle, add metal-cpp submodule, format

src/core/kernel/kernel.cpp

@@ -82,7 +82,7 @@ void Kernel::setVersion(u8 major, u8 minor) {
 	mem.kernelVersion = descriptor; // The memory objects needs a copy because you can read the kernel ver from config mem
 }
 
-Handle Kernel::makeProcess(u32 id) {
+HorizonHandle Kernel::makeProcess(u32 id) {
 	const Handle processHandle = makeObject(KernelObjectType::Process);
 	const Handle resourceLimitHandle = makeObject(KernelObjectType::ResourceLimit);