Track project webhooks and display on integration page

[agjohnson]

Webhook creation should add a webhook object to track the status of the project webhook, and allow operations on the webhooks. The integration APIs should give back an object id. We will track this and eventually allow for additional operations on the remote object or automatic updating.

• Make a per oauth service update_webhook that uses the object id and URL to update the webhook object. It might make sense to break up some of the functionality around oauth services.
• Figure out if we want a pattern that uses a through model for Integrations. This could either use a generic relation to actual integration types, or we could just make a generic skeleton for integration types.
• UI for singular webhook resync
• API webhook responses into an auto created webhook object
• Difference between auto created webhooks from intermediate webhook views and explicit integration views. Don't show sync button?
• Do something with the weird UI around missing a project webhook
• Generic brute force webhook creation when missing new project bits?
• Handle integration with missing data before sync operation. Perhaps syncing on a webhook like this defaults to trying to create the webhook? This should avoid recreating a webhook on our side though.
• Filter some of the headers we don't want to display
• Admin views

Later:

• Create webhook UI? This would rely on the remote repo object connected to the project. We would use this to try to create a webhook