A new test is added to verify that contextual logs are reflected back to
the LSP client. In the future when we are considering servers with
multiple clients, this test will be used to verify that client log
exporting is scoped to the specific client session.
Updates golang/go#34111.
Change-Id: I29044e5355e25b81a759d064929520345230ea82
Reviewed-on: https://go-review.googlesource.com/c/tools/+/215739
Reviewed-by: Rebecca Stambler <rstambler@golang.org>