Unhandled HTML response from GCP

[POD666]

Sometimes GCP responds with html for errors, e.g. 404 when using a wrong topic name.

While it's easy to find and fix a typo in a topic name during development, sometimes unknown errors occur.

Here is all I see for an unexpected issue in sentry:

So, it would be nice to add handling for HTML responses from GCP.

Here and other methods: https://github.com/sagi/workers-pubsub/blob/master/src/topics.js#L31