Add ARM64 value to hxp.HostArchitecture

[tobil4sk]

ARM64 should be added to hxp.HostArchitecture, and all usages should be updated accordingly:
https://github.com/openfl/hxp/search?q=HostArchitecture

Also need to update ndll paths for arm64 systems (MacArm64, LinuxArm64 etc):

hxp/src/hxp/Haxelib.hx

Lines 180 to 191 in d43052e

	if (System.hostPlatform == WINDOWS)
	{
	directoryName = "Windows";
	}
	else if (System.hostPlatform == MAC)
	{
	directoryName = System.hostArchitecture == X64 ? "Mac64" : "Mac";
	}
	else
	{
	directoryName = System.hostArchitecture == X64 ? "Linux64" : "Linux";
	}