(core) Adding new column in users table "ref" with unique identifier.

Summary:
There is a new column in users table called ref (user reference).
It holds user's unique reference number that can be used for features
that require some kind of ownership logic (like comments).

Test Plan: Updated tests

Reviewers: georgegevoian, paulfitz

Reviewed By: georgegevoian, paulfitz

Differential Revision: https://phab.getgrist.com/D3641

app/server/lib/DocManager.ts

@@ -261,7 +261,7 @@ export class DocManager extends EventEmitter {
    *      `doc` - the object with metadata tables.
    */
   public async openDoc(client: Client, docId: string,
-                       mode: OpenDocMode = 'default',
+                       openMode: OpenDocMode = 'default',
                        linkParameters: Record<string, string> = {}): Promise<OpenLocalDocResult> {
     let auth: Authorizer;
     const dbManager = this._homeDbManager;
@@ -271,6 +271,7 @@ export class DocManager extends EventEmitter {
       const org = client.getOrg();
       if (!org) { throw new Error('Documents can only be opened in the context of a specific organization'); }
       const userId = await client.getUserId(dbManager) || dbManager.getAnonymousUserId();
+      const userRef = await client.getUserRef(dbManager);
 
       // We use docId in the key, and disallow urlId, so we can be sure that we are looking at the
       // right doc when we re-query the DB over the life of the websocket.
@@ -284,7 +285,15 @@ export class DocManager extends EventEmitter {
         // than a docId.
         throw new Error(`openDoc expected docId ${docAuth.docId} not urlId ${docId}`);
       }
-      auth = new DocAuthorizer(dbManager, key, mode, linkParameters, docAuth, client.getProfile() || undefined);
+      auth = new DocAuthorizer({
+        dbManager,
+        key,
+        openMode,
+        linkParameters,
+        userRef,
+        docAuth,
+        profile: client.getProfile() || undefined
+      });
     } else {
       log.debug(`DocManager.openDoc not using authorization for ${docId} because GRIST_SINGLE_USER`);
       auth = new DummyAuthorizer('owners', docId);
@@ -302,7 +311,7 @@ export class DocManager extends EventEmitter {
 
       // If opening in (pre-)fork mode, check if it is appropriate to treat the user as
       // an owner for granular access purposes.
-      if (mode === 'fork') {
+      if (openMode === 'fork') {
         if (await activeDoc.canForkAsOwner(docSession)) {
           // Mark the session specially and flush any cached access
           // information.  It is easier to make this a property of the