Rework module parsing and execution (#4462)

This patch disables automatic detection of module code, and instead
requires the user to explicitly specify whether to parse a source
as a module or as a script.

To achieve this the jerry_parse API function now takes a new option
which signals that the source should be parsed as a module.

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai daniel.batyai@h-lab.eu

jerry-core/parser/js/js-parser-util.c

@@ -1396,7 +1396,7 @@ parser_error_to_string (parser_error_t error) /**< error code */
     }
     case PARSER_ERR_MODULE_UNEXPECTED:
     {
-      return "Import and export statements must be in the global context.";
+      return "Unexpected import or export statement.";
     }
     case PARSER_ERR_LEFT_BRACE_MULTIPLY_EXPECTED:
     {