This fixes a regression in 93678e89cd
and a4979410f9, where the webhooks using
authenticated_rest_api_view were migrated to a new model that didn't
include setting a custom Client string for the webhook.
When restoring these webhooks' client strings, we also fix places
where the client string was not capitalized the same was as the
product's name.
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.
This commit migrates all webhooks to use check_send_stream_message
instead of check_send_message. The only two webhooks that still
use check_send_message are our yo and teamcity webhooks. They
both use check_send_message for private messages.
