Add support for Polls

Co-authored-by: owocado <24418520+owocado@users.noreply.github.com>
Co-authored-by: Josh <8677174+bijij@users.noreply.github.com>
Co-authored-by: Trevor Flahardy <75498301+trevorflahardy@users.noreply.github.com>

discord/http.py

@@ -68,6 +68,7 @@ if TYPE_CHECKING:
     from .embeds import Embed
     from .message import Attachment
     from .flags import MessageFlags
+    from .poll import Poll
 
     from .types import (
         appinfo,
@@ -91,6 +92,7 @@ if TYPE_CHECKING:
         sticker,
         welcome_screen,
         sku,
+        poll,
     )
     from .types.snowflake import Snowflake, SnowflakeList
 
@@ -154,6 +156,7 @@ def handle_message_parameters(
     thread_name: str = MISSING,
     channel_payload: Dict[str, Any] = MISSING,
     applied_tags: Optional[SnowflakeList] = MISSING,
+    poll: Optional[Poll] = MISSING,
 ) -> MultipartParameters:
     if files is not MISSING and file is not MISSING:
         raise TypeError('Cannot mix file and files keyword arguments.')
@@ -256,6 +259,9 @@ def handle_message_parameters(
         }
         payload.update(channel_payload)
 
+    if poll not in (MISSING, None):
+        payload['poll'] = poll._to_dict()  # type: ignore
+
     multipart = []
     if files:
         multipart.append({'name': 'payload_json', 'value': utils._to_json(payload)})
@@ -2513,6 +2519,43 @@ class HTTPClient:
         payload = {k: v for k, v in payload.items() if k in valid_keys}
         return self.request(Route('PATCH', '/applications/@me'), json=payload, reason=reason)
 
+    def get_poll_answer_voters(
+        self,
+        channel_id: Snowflake,
+        message_id: Snowflake,
+        answer_id: Snowflake,
+        after: Optional[Snowflake] = None,
+        limit: Optional[int] = None,
+    ) -> Response[poll.PollAnswerVoters]:
+        params = {}
+
+        if after:
+            params['after'] = int(after)
+
+        if limit is not None:
+            params['limit'] = limit
+
+        return self.request(
+            Route(
+                'GET',
+                '/channels/{channel_id}/polls/{message_id}/answers/{answer_id}',
+                channel_id=channel_id,
+                message_id=message_id,
+                answer_id=answer_id,
+            ),
+            params=params,
+        )
+
+    def end_poll(self, channel_id: Snowflake, message_id: Snowflake) -> Response[message.Message]:
+        return self.request(
+            Route(
+                'POST',
+                '/channels/{channel_id}/polls/{message_id}/expire',
+                channel_id=channel_id,
+                message_id=message_id,
+            )
+        )
+
     async def get_gateway(self, *, encoding: str = 'json', zlib: bool = True) -> str:
         try:
             data = await self.request(Route('GET', '/gateway'))