When the kvdb to sql migration is initially introduced, we will want to
ensure that it is only run under dev builds during the testing phase.
We therefore introduce the functionality to have separate dev
migrations, which are only included in a separate migration stream that
is used only in dev builds.
Note that these dev migrations are currently not included in the
`sqlc.yaml` file, to ensure that the main sqlc models doesn't include
the dev migrations.
This commit also contains the sqlc.yaml file, the `make sqlc` command
and the script for generating sqlc code. This must be done in this
commit as the script only works if there are queries to generate from.