Refactor includes structure, getting rid of rust_internal.h

Many changes to code structure are included:
- removed TIME_SLICE_IN_MS
- removed sychronized_indexed_list
- removed region_owned
- kernel_owned move to kernel.h, task_owned moved to task.h
- global configs moved to rust_globals.h
- changed #pragma once to standard guard in rust_upcall.h
- got rid of memory.h

src/rt/rust_kernel.cpp

@@ -1,4 +1,7 @@
-#include "rust_internal.h"
+
+#include "rust_kernel.h"
+#include "rust_globals.h"
+#include "rust_port.h"
 #include "rust_util.h"
 #include "rust_scheduler.h"