Assorted fixes (#157)

* feat(GtaThread): add force cleanup fields

* fix(scrThreadContext): there is no TIMER_C

* feat(GtaThread): add the flag

* fix(scrProgram): add scrNativeHandler include

* fix(scrNativeHandler): make data fields public

---------

Co-authored-by: maybegreat48 <email@hostname>

script/scrNativeHandler.hpp

@@ -46,7 +46,7 @@ namespace rage
 		{
 			*reinterpret_cast<std::remove_cv_t<std::remove_reference_t<T>>*>(m_return_value) = std::forward<T>(value);
 		}
-	protected:
+
 		void* m_return_value;
 		std::uint32_t m_arg_count;
 		void* m_args;