Finish annotating query_items parameters in builder.py.

- These are passed into `urllib.parse.urlencode()`, so the annotation for that was copied from typeshed and modified slightly.
 - `_QueryType` in typeshed uses `typing.Sequence` to account for different types of sequence values being passed in, but `URLBuilder.extend_query_with()` in builder.py uses `isinstance(query_items, list)` as flow control, so Sequence is too wide to account for what that method allows. Thus, the type was modified to use `typing.List` in place of `typing.Sequence` where necessary.
 - Arguably, that isinstance check should be changed to check against `Sequence` instead, but I'd prefer having that double-checked, and this PR's scope is currently mostly limited to annotations anyway. This can be revisited later if necessary.
- TODO: Ask if `username is None` check is still needed in `URLBuilder.add_credentials()` if the `username` parameter is annotated with `str`.

Author: Sachaa-Thanasius

src/rfc3986/builder.py

@@ -20,6 +20,14 @@
 from . import uri
 from . import uri_reference
 
+# Copied from urllib.parse in typeshed.
+_QueryType = t.Union[
+    t.Mapping[t.Any, t.Any],
+    t.Mapping[t.Any, t.Sequence[t.Any]],
+    t.List[t.Tuple[t.Any, t.Any]],
+    t.List[t.Tuple[t.Any, t.Sequence[t.Any]]],
+]
+
 
 class URIBuilder:
     """Object to aid in building up a URI Reference from parts.
@@ -268,7 +276,7 @@ def extend_path(self, path: str):
 
         return self.add_path(path)
 
-    def add_query_from(self, query_items):
+    def add_query_from(self, query_items: _QueryType):
         """Generate and add a query a dictionary or list of tuples.
 
         .. code-block:: python
@@ -294,7 +302,7 @@ def add_query_from(self, query_items):
             fragment=self.fragment,
         )
 
-    def extend_query_with(self, query_items):
+    def extend_query_with(self, query_items: _QueryType):
         """Extend the existing query string with the new query items.
 
         .. versionadded:: 1.5.0