fix: some bugs (#10)

* feat: check if the region exists before trying assignation

* fix: agent client exec path

fix: runtime registries auth

fix: wrong working dir in initd

fix: allow to destroy "created" instance

fix: initd exec endpoint

feat: add machine gateways

fix: wrong jailer binary path

fix: ravel proxy cert-loading

chore: use pgx for corrosion queries

feat: introduce the new initd