pd: `Routes` added to tonic server cause regression in http trailers

[conorsch]

We observed a breaking change in the local dev env for web extension development this morning, caused by merge of #3679. Although that PR passed smokes and even manual testing via pcli, it broke the web extension, due to the refactor no longer supporting HTTP trailers.

For now, we'll revert that commit, to unbreak web development immediately. We should also investigate how to improve integration testing between the penumbra monorepo and the latest tip of extension code.

Misc

@hdevalence isolated the failing commit via git bisect.

[cratelyn]

hyperium/tonic#455 notes two unfinished issues:

• Decide how to better integrate this functionality with the transport. For now, the GrpcWeb type is designed to decorate services but it doesn't have to be. A different design might not even expose the service and wire everything up internally.
• How to better integrate with tonic's router. To multiplex services, it is necessary to wrap them individually. This is either a feature or a bug.

(emphasis mine)

i suspect that the change to use a Routes in #3679 was adversely affected by this.

i'll take a look tomorrow, but i plan to keep a tight timebox on attempting to land that PR again, as written. it was addressing a TODO that i found while working on auto-https. i may remove that comment, or rewrite it to point here.

it would be nice to test pd against a grpc-web client, if we do not already. that feels outside the scope of this issue.

thanks for opening this and for reverting that commit, @conorsch! (and thank you to everybody else that helped track this regression 🐛 🔍)

[hdevalence]

Another possibility is that we could file an issue upstream, and then keep the commit around to pull up again if it gets resolved -- the new code is certainly nicer but i'm not sure it's critical to land it at the moment.

[cratelyn]

note: i filed #3704 to track the addition of integration tests exercising grpc-web compatibility, to keep that conversation separate from this specific regression.