webhooks: Migrate most integrations to use check_send_webhook_message.

This commit migrates all of our webhooks to use
check_send_webhook_message, except the following:

beeminder: Rishi wanted to wait on this one.
teamcity: This one is slightly more work.

yo: This one is PM-only. I am still trying to decide whether we
    should have a force_private argument or something in
    check_send_webhook_message.

facebook: No point in migrating this, will be removed as part of
          #8433.

slack: Slightly more work too with the `channel_to_topics` feature.
       Warrants a longer discussion.

zerver/webhooks/homeassistant/view.py

@@ -4,17 +4,16 @@ from django.http import HttpRequest, HttpResponse
 from django.utils.translation import ugettext as _
 
 from zerver.decorator import api_key_only_webhook_view
-from zerver.lib.actions import check_send_stream_message
 from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.response import json_error, json_success
+from zerver.lib.webhooks.common import check_send_webhook_message
 from zerver.lib.validator import check_dict, check_string
 from zerver.models import UserProfile
 
 @api_key_only_webhook_view('HomeAssistant')
 @has_request_variables
 def api_homeassistant_webhook(request: HttpRequest, user_profile: UserProfile,
-                              payload: Dict[str, str]=REQ(argument_type='body'),
-                              stream: Text=REQ(default="homeassistant")) -> HttpResponse:
+                              payload: Dict[str, str]=REQ(argument_type='body')) -> HttpResponse:
 
     # construct the body of the message
     body = payload["message"]
@@ -26,7 +25,7 @@ def api_homeassistant_webhook(request: HttpRequest, user_profile: UserProfile,
         topic = "homeassistant"
 
     # send the message
-    check_send_stream_message(user_profile, request.client, stream, topic, body)
+    check_send_webhook_message(request, user_profile, topic, body)
 
     # return json result
     return json_success()