utr: Wrap recipes.py invocations in `rdb stream`

The chromium recipe needs an rdb invocation in its context so that it
can fetch the results of any tests it triggers. (The chromium recipe
migrated away from json test results a while ago.)

So this has the utr wrap recipe invocations in
`rdb stream -new -- ...` which will create an rdb invocation for the
duration of the recipe. It also adds some checking for rdb auth
to improve UX in case the user isn't auth'ed beforehand.

Bug: 41492688
Change-Id: Iba6b65a83c86a261069b3f84d1e91648c63f15b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5329545


Reviewed-by: Struan Shrimpton <sshrimp@google.com>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1267176}