Webhost: Disallow empty option groups (#3369)

* move item_and_loc_options out of the meta class and into the Options module

* don't allow empty world specified option groups

* reuse option_group generation code instead of rewriting it

* delete the default group if it's empty

* indent

worlds/AutoWorld.py

@@ -10,10 +10,7 @@ from dataclasses import make_dataclass
 from typing import (Any, Callable, ClassVar, Dict, FrozenSet, List, Mapping, Optional, Set, TextIO, Tuple,
                     TYPE_CHECKING, Type, Union)
 
-from Options import (
-    ExcludeLocations, ItemLinks, LocalItems, NonLocalItems, OptionGroup, PerGameCommonOptions,
-    PriorityLocations, StartHints, StartInventory, StartInventoryPool, StartLocationHints
-)
+from Options import item_and_loc_options, OptionGroup, PerGameCommonOptions
 from BaseClasses import CollectionState
 
 if TYPE_CHECKING:
@@ -119,12 +116,11 @@ class WebWorldRegister(type):
         # don't allow an option to appear in multiple groups, allow "Item & Location Options" to appear anywhere by the
         # dev, putting it at the end if they don't define options in it
         option_groups: List[OptionGroup] = dct.get("option_groups", [])
-        item_and_loc_options = [LocalItems, NonLocalItems, StartInventory, StartInventoryPool, StartHints,
-                                StartLocationHints, ExcludeLocations, PriorityLocations, ItemLinks]
         seen_options = []
         item_group_in_list = False
         for group in option_groups:
             assert group.name != "Game Options", "Game Options is a pre-determined group and can not be defined."
+            assert group.options, "A custom defined Option Group must contain at least one Option."
             if group.name == "Item & Location Options":
                 group.options.extend(item_and_loc_options)
                 item_group_in_list = True