Add macOS simulator build to pipelines (#162)

- GitHub actions changed to build simulator on macOS (it's broken, but at least we get a good code portability check for now!)
- `Buildscripts/` shell scripts updated to use `/bin/sh` so it works on macOS too
- Various includes fixed in various subprojects so the code is more portable

Buildscripts/release-simulator.sh

@@ -1,4 +1,4 @@
-#!/usr/bin/bash
+#!/bin/sh
 
 #
 # Usage: release-simulator.sh [builddir] [target_path]