Remove ES_NEXT macro (#4915)

- remove all '#JERRY_ESNEXT' macro
- remove 5.1 build profile, update test runner accordingly (Note: all builtins are turn on by default)
- move tests from tests/jerry/esnext into tests/jerry, concatenate files with same names
- add skiplist to some snapshot tests that were supported only in 5.1
- fix doxygen issues that were hidden before (bc. of es.next macro)

Co-authored-by: Martin Negyokru negyokru@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Adam Szilagyi aszilagy@inf.u-szeged.hu

jerry-core/ecma/builtin-objects/ecma-builtin-global.c

@@ -100,12 +100,10 @@ ecma_builtin_global_object_eval (ecma_value_t x) /**< routine's first argument *
     parse_opts |= ECMA_PARSE_STRICT_MODE;
   }
 
-#if JERRY_ESNEXT
   if (vm_is_direct_eval_form_call ())
   {
     parse_opts |= ECMA_GET_LOCAL_PARSE_OPTS ();
   }
-#endif /* JERRY_ESNEXT */
 
   /* steps 2 to 8 */
   return ecma_op_eval (x, parse_opts);