A pull that starts waiting on a team's review shows one line in that team's members' feed #10164

For: the team is told once, where they already look, instead of finding out on the pull.

Done looks like:

• [x] When a pull first becomes held by a named team (src/actions/issue_teams.ts decides; src/actions/pulls.ts or the review path emits), one bus event; its members who can read the repository see "acme/demo#12 waits on Design's review".
• [x] No second line while it stays held; approval by the team ends it.
• [x] Tests: members see it once, non-members do not, title escaped.

Reviewed pull #10166 at its head: ticked When a pull first becomes held by a named team (src/actions/issue_teams.ts decides; src/actions/pulls.ts or the review path emits), one bus event; its members who can read the repository see "acme/demo#12 waits on Design's review".; No second line while it stays held; approval by the team ends it.; Tests: members see it once, non-members do not, title escaped..