[BOW-34] Move Prisma client to separate helper package

[markspolakovs]

No description provided.

[linear]

BOW-34 CI flake caused by addition of `postinstall` Prisma generation

Happens very often, and is usually fixed by rerunning the failed jobs. Probable cause is the Prisma client getting cached in node_modules, and a subsequent cache tripping up on it.

Likely fix is the same that was mooted in BOW-29, which is to move the Prisma client generation (and Zod types) to a separate package that all the others depend on (similar to https://github.com/calcom/cal.com/tree/main/packages/prisma).