Remove incomplete grants system

Problem/Motivation

The current implementation of the hook_node_grants() and hook_node_access_records() is incomplete because it doesn't explicitly grant access to published content. This results in any content with editors/reviewers not being viewable by other users, even when published since there are only workflow participant records in the node_access table.

Proposed resolution

Remove these implementations, since hook_entity_access is already implemented. Potentially revisit adding these in the future in a more fleshed out manner.

Remaining tasks

User interface changes

API changes

Data model changes