Recognize known errors during commit and do not error out fatally

[sdnts]

Currently, any and all errors that originate when you Save Changes back to your DB are considered fatal, and require you to either refresh the page, or discard all your changes and reset. This is far from ideal. This also includes user errors (like constraint failures)

If we can recognize certain errors from Prisma Client's error codes, we can show suitable error messages and not fail fatally, allowing people to correct their entry.

Error docs: https://www.prisma.io/docs/reference/tools-and-interfaces/prisma-client/error-reference