Expose Prisma types as Wasp imports

[sodic]

Until we implement full-stack type support in Wasp , we should make entity types Prisma generates available to our users on both the server and the client.

NOTE: We need to make sure Prisma types cannot contain anything server-specific in terms of runtime.

This is how the usage might look like:

import { Task } from '@wasp/entities/Task'

// ...

const { data: tasks } = useQuery<Task[]>(...)

[sodic]

Not quite closed yet, but close to closing :)