Make the DB name a suffix of the first part of jobs' name

!10946 (merged) broke the migration path mysql jobs because scripts/prepare_build.sh expect the DB name to be the second part of the job's name. This was reverted in !11037 (merged).

This is a bit silly and error-prone. A good first step would be to move the DB name as the last part of the job's name as this is not the most important part.

/cc @DouweM @godfat

mentioned in merge request !11042 (merged)

assigned to @rymai

changed title from Make the DB name the last part of jobs' name to Make the DB name a suffix of the first part of jobs' name

changed milestone to %9.3

closed via merge request !11042 (merged)