(core) make SELF_HYPERLINK urls cleaner

Summary:
This cleans up a few things about SELF_HYPERLINK urls:

 * Use `urlId` rather than `docId`.
 * Correctly merge personal org subdomain.
 * In dev environment, use clearer port number.

Test Plan: updated test

Reviewers: alexmojaki, dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2841

app/server/lib/FlexServer.ts

@@ -1147,7 +1147,7 @@ export class FlexServer implements GristServer {
       state.ws = resource.id;
     } else {
       org = resource.workspace.org;
-      state.doc = resource.id;
+      state.doc = resource.urlId || resource.id;
       state.slug = getSlugIfNeeded(resource);
     }
     state.org = this.dbManager.normalizeOrgDomain(org.id, org.domain, org.ownerId);