(core) Enable auto triggering of Welcome Tour, and various improvements.

Summary:
- Add showGristTour preference, and trigger tour automatically.
- Tour is only triggered for new and anonymous users on a personal org, with
  edit permission.

- Automatically open the right panel at tour start.
- Don't show tours on mobile, since that's not ready (popups are cut off
  and can't be dismissed)
- Cancel previous tour if a new one is somehow started.
- Remove #repeat- trigger hash tags from the URL when the tour starts.
- Ensure Help Center popup is positioned even when left panel is collapsed.
- Polish up the content of the last two cards in the tour.

Test Plan: Added test case for triggering and opening right panel.

Reviewers: alexmojaki, paulfitz

Reviewed By: alexmojaki

Differential Revision: https://phab.getgrist.com/D2955

app/client/ui/LeftPanelCommon.ts

@@ -30,17 +30,17 @@ export function createHelpTools(appModel: AppModel, spacer = true): DomContents
     spacer ? cssSpacer() : null,
     cssPageEntry(
       cssPageLink(cssPageIcon('Feedback'),
-        cssLinkText('Give Feedback', dom.cls('tour-feedback')),
+        cssLinkText('Give Feedback'),
         dom.on('click', () => beaconOpenMessage({appModel})),
       ),
       dom.hide(isEfcr),
       testId('left-feedback'),
     ),
     cssPageEntry(
-      cssPageLink(cssPageIcon('Help'), {href: commonUrls.help, target: '_blank'}, cssLinkText(
-        'Help Center',
+      cssPageLink(cssPageIcon('Help'), {href: commonUrls.help, target: '_blank'},
+        cssLinkText('Help Center'),
         dom.cls('tour-help-center')
-      )),
+      ),
       dom.hide(isEfcr),
     ),
   ];