lua: add sj.get_module_namespace

sjasm/lua_sjasm.cpp

@@ -338,6 +338,10 @@ static unsigned int lua_sj_get_word(unsigned int address) {
 	return result;
 }
 
+static const char* lua_sj_get_module(void) {
+	return ModuleName;
+}
+
 static bool lua_zx_trdimage_create(const char* trdname, const char* label = nullptr) {
 	// setup label to truncated 8 char array padded with spaces
 	char l8[9] = "        ";
@@ -406,6 +410,7 @@ static void lua_impl_init() {
 			.addFunction("get_byte", lua_sj_get_byte)
 			.addFunction("get_word", lua_sj_get_word)
 			.addFunction("get_device", GetDeviceName)		// no error/warning, can be called directly
+			.addFunction("get_module_namespace", lua_sj_get_module)
 			.addFunction("set_page", lua_sj_set_page)
 			.addFunction("set_slot", lua_sj_set_slot)
 			// MMU API will be not added, it is too dynamic, and _pc("MMU ...") works