✨ 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/schema_extra_example/tutorial003.py

@@ -17,7 +17,6 @@ class Item(BaseModel):
 async def update_item(
     item_id: int,
     item: Item = Body(
-        ...,
         example={
             "name": "Foo",
             "description": "A very nice Item",