(core) granular access control in the presence of schema changes

Summary:
 - Support schema changes in the presence of non-trivial ACL rules.
 - Fix update of `aclFormulaParsed` when updating formulas automatically after schema change.
 - Filter private metadata in broadcasts, not just fetches.  Censorship method is unchanged, just refactored.
 - Allow only owners to change ACL rules.
 - Force reloads if rules are changed.
 - Track rule changes within bundle, for clarity during schema changes - tableId and colId changes create a muddle otherwise.
 - Show or forbid pages dynamically depending on user's access to its sections. Logic unchanged, just no longer requires reload.
 - Fix calculation of pre-existing rows touched by a bundle, in the presence of schema changes.
 - Gray out acl page for non-owners.

Test Plan: added tests

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2734

app/client/models/DocPageModel.ts

@@ -294,18 +294,18 @@ function addMenu(importSources: ImportSource[], gristDoc: GristDoc, isReadonly:
   const selectBy = gristDoc.selectBy.bind(gristDoc);
   return [
     menuItem(
-      (elem) => openPageWidgetPicker(elem, gristDoc.docModel, (val) => gristDoc.addNewPage(val),
+      (elem) => openPageWidgetPicker(elem, gristDoc.docModel, (val) => gristDoc.addNewPage(val).catch(reportError),
                                      {isNewPage: true, buttonLabel: 'Add Page'}),
       menuIcon("Page"), "Add Page", testId('dp-add-new-page'),
       dom.cls('disabled', isReadonly)
     ),
     menuItem(
-      (elem) => openPageWidgetPicker(elem, gristDoc.docModel, (val) => gristDoc.addWidgetToPage(val),
+      (elem) => openPageWidgetPicker(elem, gristDoc.docModel, (val) => gristDoc.addWidgetToPage(val).catch(reportError),
                                      {isNewPage: false, selectBy}),
       menuIcon("Widget"), "Add Widget to Page", testId('dp-add-widget-to-page'),
       dom.cls('disabled', isReadonly)
     ),
-    menuItem(() => gristDoc.addEmptyTable(), menuIcon("TypeTable"), "Add Empty Table", testId('dp-empty-table'),
+    menuItem(() => gristDoc.addEmptyTable().catch(reportError), menuIcon("TypeTable"), "Add Empty Table", testId('dp-empty-table'),
             dom.cls('disabled', isReadonly)),
     menuDivider(),
     ...importSources.map((importSource, i) =>

app/client/models/errors.ts

@@ -48,6 +48,10 @@ export function getAppErrors(): string[] {
  */
 export function reportError(err: Error|string): void {
   log.error(`ERROR:`, err);
+  if (String(err).match(/GristWSConnection disposed/)) {
+    // This error can be emitted while a page is reloaded, and isn't worth reporting.
+    return;
+  }
   _logError(err);
   if (_notifier && !_notifier.isDisposed()) {
     if (!isError(err)) {