(core) Implement much of the general AccessRules UI.

Summary:
- Factored out ACLRuleCollection into its own file, and use for building UI.
- Moved AccessRules out of UserManager to a page linked from left panel.
- Changed default RulePart to be the last part of a rule for simpler code.
- Implemented much of the UI for adding/deleting rules.
  - For now, editing the ACLFormula and Permissions is done using text inputs.
- Implemented saving rules by syncing a bundle of them.
- Fixed DocData to clean up action bundle in case of an early error.

Test Plan: WIP planning to add some new browser tests for the UI

Reviewers: paulfitz

Reviewed By: paulfitz

Differential Revision: https://phab.getgrist.com/D2678

app/client/models/gristUrlState.ts

@@ -86,8 +86,6 @@ function _getLoginLogoutUrl(method: 'login'|'logout'|'signin', nextUrl: string):
   return startUrl.href;
 }
 
-export type IDocPage = number | 'new' | 'code';
-
 /**
  * Implements the interface expected by UrlState. It is only exported for the sake of tests; the
  * only public interface is the urlState() accessor.