✨ Add support for not needing ... as default value in required Query(), Path(), Header(), etc. (#4906)

* ✨ Do not require default value in Query(), Path(), Header(), etc

* 📝 Update source examples for docs with default and required values

* ✅ Update tests with new default values and not required Ellipsis

* 📝 Update docs for Query params and update info about default value, required, Ellipsis

docs_src/dependencies/tutorial005.py

@@ -10,7 +10,7 @@ def query_extractor(q: Optional[str] = None):
 
 
 def query_or_cookie_extractor(
-    q: str = Depends(query_extractor), last_query: Optional[str] = Cookie(None)
+    q: str = Depends(query_extractor), last_query: Optional[str] = Cookie(default=None)
 ):
     if not q:
         return last_query