Add wshim support

[mendess]

No description provided.

[cjpatton]

Noooicce! Just one minor comment.

@rozbb can you test out ct_worker? I've already tested mtc_worker.

[rozbb]

Probably dumb question, but I'm not familiar with this pattern: what is a wshim and what is it intended to do? My guess: it is an object that knows how to serialize a log/registry/whatever to a particular endpoint that can be used for monitoring.

Another dumb question: why is this necessary when wrangler tail exists? Is this a common workaround to some known limitations in wrangler tail? Could it possibly be moved into a library eventually?

Finally, it'd be nice to have some comments explaining what's happening. This PR meaningfully increases complexity due to mutability and scoping tricks. It'd be good to make sure this is explained fully. And hopefully, written in a way that it can eventually be removed once we get a better logging story for wrangler.

[rozbb]

Noooicce! Just one minor comment.

@rozbb can you test out ct_worker? I've already tested mtc_worker.

npx wrangler dev -e dev followed by python3 scripts/add_cert_to_local_dev.py seems to work. That is, the request is a success and the tree eventually has 1 item.