subscription: Include archived channels in streams list.

`is_archived` field is added to the stream and types.

Include a new `archived_channeels` client capability, to allow clients
to access data on archived channels, without breaking
backwards-compatibility for existing clients that don't know how to
handle these.

Also, included `exclude_archived` parameter to `/get-streams`,
which defaults to `true` as basic clients may not be interested
in archived streams.

zerver/tornado/django_api.py

@@ -91,6 +91,7 @@ def request_event_queue(
     linkifier_url_template: bool = False,
     user_list_incomplete: bool = False,
     include_deactivated_groups: bool = False,
+    archived_channels: bool = False,
 ) -> str | None:
     if not settings.USING_TORNADO:
         return None
@@ -115,6 +116,7 @@ def request_event_queue(
         "linkifier_url_template": orjson.dumps(linkifier_url_template),
         "user_list_incomplete": orjson.dumps(user_list_incomplete),
         "include_deactivated_groups": orjson.dumps(include_deactivated_groups),
+        "archived_channels": orjson.dumps(archived_channels),
     }
 
     if event_types is not None: