JiHu - How to identify JiHu specific structure changes

During a discussion around [Organize Code] Add migrations in JH repo it was indicated that it might be helpful to identify structure changes to our database that are specific to a JiHu migration so that they are not inadvertently dropped in a subsequent GitLab migration. One suggestion was to add a Postgres Column Comment, however this comes with its own trade-offs such as requiring a migration to simply update a column. Another suggestion was to possibly use schemas to identify JiHu contributions. More context here https://docs.google.com/document/d/1k_hPZloF_2J1PCz8_cI_E1Ld1Gu759KOJkspJ_L-QvQ/edit#bookmark=id.4vs848ijwx2h

The intention of this issue is to identify a way for maintainers and developers to quickly identify JiHu specific changes to the database.