adding count resolver for findmany

Hi,
it would be amazing if there would be a count resolver to a findMany resolver.
I know it could be a problem because you would have to make another query to the DB to get the count so even a dedicated resolver for the count that will look like this CountXResolver.ts would make the job.

Start by locating the generated findMany resolver and the proposed CountXResolver.ts pattern. Clarify whether the count should be a separate resolver or part of findMany, how it should query the database, and what generated GraphQL API is expected; done means the generator emits the agreed count capability.

Written by the indexing model from the issue text.