[TOOLING] State consistency between db and ground truth

[seaerchin]

Problem

After #459, we have a mechanism of creating sites automatically through using formsg. however, we still do not have rollback mechanisms. this implies that when a site fails to create, there will be a site record created within our database, which is inconsistent with the ground truth.

Hence, there's a need for a rollback mechanism to be implemented across our services so that when any step in particular fails, the artefacts of that step is rolled back so that our db is logically consistent with the ground truth

related to #453