database: Fix the builds limit issue.

Fixes <https://bugs.gnu.org/32300>.

* src/cuirass/database.scm (filters->order): New procedure.
(db-get-builds): Remove FORMAT-OUTPUT, CONS-OUTPUT, COLLECT-OUTPUTS,
FINISH-GROUP, SAME-GROUP?, GROUP-OUTPUTS procedures.  Remove the 'LEFT JOIN
Outputs' clause.  Use DB-GET-OUTPUTS for each build that was fetched.