[push-api] Remove PushManager#hasPermission in favor of Permissions API (#109)

The Permissions API [1] is likely to provide a generalized way to check the permission status of a large number of APIs, including the Push API. It seems likely we can omit the PushManager#hasPermission method from the Push API.

Talking as a Chrome implementer, I think we might initially ship without hasPermission for this reason, to wait and see if the Permissions API gains sufficient momentum in the near term.

[1] https://w3c.github.io/permissions/

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/push-api/issues/109