Armeria: Provide a way to invoke Thrift `*.AsyncIface` implementations via `blockingTaskExecutor`.

[trustin]

We need something similar to GrpcServiceBuilder.useBlockingTaskExecutor() in Thrift, e.g. THttpService.builder().useBlockingTaskExecutor(...).build().

/cc @delegacy

[delegacy]

Will prepare a PR soon.

[delegacy]

Sorry for a really long consideration, but... 😅

I'm thinking this does not introduce any advantage because normally users must implement AsyncIface in an asynchronous way. I feel like this feature just allows users to make mistakes. (blocking implementation in AsyncIface)

Any thought?

[anuraaga]

Agree that unlike gRPC thrift doesn't really need it since there are two types of interface classes.

[trustin]

Let me close this issue, then. Please feel free to create a new issue if the situation has changed.