(core) Remove the aclUI=1 flag and add 'BETA' tag to the Access Rules page name.

Summary:
- Remove support for aclUI=1 URL parameter, making it the default.
- Add 'BETA' tag to the Access Rules link in side panel.
- Remove all mentions of aclUI=1 in tests.

Test Plan: Updated tests should pass

Reviewers: paulfitz

Reviewed By: paulfitz

Differential Revision: https://phab.getgrist.com/D2766

app/common/gristUrls.ts

@@ -65,7 +65,6 @@ export interface IGristUrlState {
     embed?: boolean;
     style?: InterfaceStyle;
     compare?: string;
-    aclUI?: boolean;
     linkParameters?: Record<string, string>;  // Parameters to pass as 'user.Link' in granular ACLs.
                                               // Encoded in URL as query params with extra '_' suffix.
   };
@@ -265,9 +264,6 @@ export function decodeUrl(gristConfig: Partial<GristLoadConfig>, location: Locat
   if (sp.has('compare')) {
     state.params!.compare = sp.get('compare')!;
   }
-  if (sp.has('aclUI')) {
-    state.params!.aclUI = isAffirmative(sp.get('aclUI'));
-  }
   for (const [k, v] of sp.entries()) {
     if (k.endsWith('_')) {
       if (!state.params!.linkParameters) { state.params!.linkParameters = {}; }