(core) Adds new view as banner

Summary:
Diff removes view-as pill in the document breadcrumbs and add new view-as banner.

Note: Banners are still missing mechanism to handle several banners. As of now both doc-usage and view-as banners could show up at the same time.

Test Plan: Refactored existing test.

Reviewers: jarek

Reviewed By: jarek

Subscribers: jarek

Differential Revision: https://phab.getgrist.com/D3732

app/client/aclui/AccessRules.ts

@@ -356,7 +356,8 @@ export class AccessRules extends Disposable {
           ),
         ),
         bigBasicButton(t('AddUserAttributes'), dom.on('click', () => this._addUserAttributes())),
-        bigBasicButton(t('Users'), cssDropdownIcon('Dropdown'), elem => this._aclUsersPopup.attachPopup(elem),
+        bigBasicButton(t('ViewAs'), cssDropdownIcon('Dropdown'),
+          elem => this._aclUsersPopup.attachPopup(elem, {placement: 'bottom-end'}),
           dom.style('visibility', use => use(this._aclUsersPopup.isInitialized) ? '' : 'hidden')),
       ),
       cssConditionError({style: 'margin-left: 16px'},