(core) Add Support Grist page and nudge

Summary:
Adds a new Support Grist page (accessible only in grist-core), containing
options to opt in to telemetry and sponsor Grist Labs on GitHub.

A nudge is also shown in the doc menu, which can be collapsed or permanently
dismissed.

Test Plan: Browser and server tests.

Reviewers: paulfitz, dsagal

Reviewed By: paulfitz

Subscribers: jarek, dsagal

Differential Revision: https://phab.getgrist.com/D3926

app/server/lib/DocApi.ts

@@ -11,7 +11,6 @@ import {
 import {isRaisedException} from "app/common/gristTypes";
 import {buildUrlId, parseUrlId} from "app/common/gristUrls";
 import {isAffirmative} from "app/common/gutil";
-import {hashId} from "app/common/hashingUtils";
 import {SchemaTypes} from "app/common/schema";
 import {SortFunc} from 'app/common/SortFunc';
 import {Sort} from 'app/common/SortSpec';
@@ -918,8 +917,8 @@ export class DocWorkerApi {
           const {forkId} = parseUrlId(scope.urlId);
           activeDoc.logTelemetryEvent(docSession, 'tutorialRestarted', {
             full: {
-              tutorialForkIdDigest: forkId ? hashId(forkId) : undefined,
-              tutorialTrunkIdDigest: hashId(tutorialTrunkId),
+              tutorialForkIdDigest: forkId,
+              tutorialTrunkIdDigest: tutorialTrunkId,
             },
           });
         }