(core) make AccessRules and FullCopies effective

Summary:
This allows `*SPECIAL:AccessRules` to give read access to the access rules to more users, and `*SPECIAL:FullCopies` to grant download/copy rights to more users.

This diff also changes forks to be owned by the user who forked them (previously they were an editor), since that feels more natural.

Test Plan: Added and updated tests.

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2760

app/client/models/entities/ACLRuleRec.ts

@@ -0,0 +1,7 @@
+import {DocModel, IRowModel} from 'app/client/models/DocModel';
+
+export type ACLRuleRec = IRowModel<"_grist_ACLRules">;
+
+export function createACLRuleRec(this: ACLRuleRec, docModel: DocModel): void {
+  // currently don't care much about content.
+}