Option to allow all filters for a model

[IlyaSemenov]

Currently, one can either allowAllFilters on graph level (which affects all queries), or allowAllFilters on model level (which affects resolving nested fields of that model).

I would like to allow filters on a certain model itself. Say if enable it for Book model, all queries to books (root queries and when books are a nested field of some other model) should be allowed to be filtered.

Proposed syntax:

export const Book = r.table(db.book, { filters: true })