Consider closing a request when the response is exceptionally completed

[jrhee17]

For certain protocols, we assume that the HttpRequest is hidden from the user well enough so we used a pooled buffer.

armeria/thrift/thrift0.13/src/main/java/com/linecorp/armeria/internal/client/thrift/THttpClientDelegate.java

Line 134 in 7f30250

final ByteBuf buf = ctx.alloc().buffer(128);

However, this may be prone to leaks if the request is never consumed.

@ikhoon has suggested that it may be more fail-proof to add a callback such that the request is aborted if response is exceptionally aborted.

ref: #5535 (comment)