refactor: change body type from dict to string in fetch command parameters

Author: thalissonvs

pydoll/commands/fetch_commands.py

@@ -200,7 +200,7 @@ def fulfill_request(  # noqa: PLR0913, PLR0917
         request_id: str,
         response_code: int,
         response_headers: Optional[list[HeaderEntry]] = None,
-        body: Optional[dict] = None,
+        body: Optional[str] = None,
         response_phrase: Optional[str] = None,
     ) -> Command[Response]:
         """

pydoll/protocol/fetch/params.py

@@ -39,7 +39,7 @@ class FulfillRequestParams(CommandParams):
     requestId: str
     responseCode: int
     responseHeaders: NotRequired[list[HeaderEntry]]
-    body: NotRequired[dict]
+    body: NotRequired[str]
     responsePhrase: NotRequired[str]