Core: some typing and docs in various parts of the interface (#1060)

* some typing and docs in various parts of the interface

* fix whitespace in docstring

Co-authored-by: black-sliver <59490463+black-sliver@users.noreply.github.com>

* suggested changes from discussion

* remove redundant import

* adjust type for json messages

* for options module detection:
 module.lower().endswith("options")

Co-authored-by: black-sliver <59490463+black-sliver@users.noreply.github.com>

test/general/TestReachability.py

@@ -20,7 +20,7 @@ class TestBase(unittest.TestCase):
                     for location in world.get_locations():
                         if location.name not in excluded:
                             with self.subTest("Location should be reached", location=location):
-                                self.assertTrue(location.can_reach(state))
+                                self.assertTrue(location.can_reach(state), f"{location.name} unreachable")
 
                     with self.subTest("Completion Condition"):
                         self.assertTrue(world.can_beat_game(state))