internal/lsp: add tracing to the didOpen call
internal/lsp: add tracing to the didOpen call

We only had the tracing on didChange before this

Change-Id: Iadec8a43d439931bf58925f149a1d32b3ae29c36
Reviewed-on: https://go-review.googlesource.com/c/tools/+/186199
Run-TryBot: Ian Cottrell <52376736e5e84615ec49f9c1843b8acc178b1d8d@google.com>
Reviewed-by: Rebecca Stambler <d7cf11e5f299d88ea8348366a9fc4f7c335c3afa@golang.org>

golang/tools,golang/tools,golang/tools,golang/tools,golang/tools