server/bigquery: extend support for computed fields in query arguments

This feature needs to be accomplished after implementing basic support for computed fields in BigQuery backends (see https://github.com/hasura/graphql-engine/issues/8521). The computed fields need to be included in,
- [ ] boolean expressions in `where` input field – filtering rows
- [ ] `order_by` fields – sorting rows

Postgres reference docs:
- sorting - https://hasura.io/docs/latest/graphql/core/databases/postgres/queries/sorting/#sorting-based-on-computed-fields
- filtering - https://hasura.io/docs/latest/graphql/core/databases/postgres/queries/query-filters/#filter-based-on-computed-fields

Start with issue #8521 for the prerequisite computed-field support, then compare the linked Postgres sorting and filtering documentation with the BigQuery backend. The work is done when computed fields are accepted in boolean expressions for filtering and in order_by fields for sorting.

Written by the indexing model from the issue text.