feat(web/panettone): Support full-text search of issues r/7828

Support basic full text search of issues using postgresql's built-in
text search. There's a new column on the issues table called `tsv`,
which contains a tsvector of the title concatenated with the
description, and a new search form on both the index and closed issues
page which allows searching that tsvector with a user-supplied query.
Results are ranked according to that text query in the case of a search.

This works fine for now, but next up I'd also like to highlight the
results according to the bits that matched the user's query.

Change-Id: I25170bedbbbcdc3ed29a047962e9fcfe280d763a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11258
Autosubmit: aspen <root@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

0 files changed, 0 insertions, 0 deletions