(core) move home server into core

Summary: This moves enough server material into core to run a home server.  The data engine is not yet incorporated (though in manual testing it works when ported).

Test Plan: existing tests pass

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2552

app/gen-server/migration/1557157922339-OrgDomainUnique.ts

@@ -0,0 +1,27 @@
+import {MigrationInterface, QueryRunner} from "typeorm";
+
+export class OrgDomainUnique1557157922339 implements MigrationInterface {
+
+  public async up(queryRunner: QueryRunner): Promise<any> {
+    const logins = (await queryRunner.getTable('orgs'))!;
+    const domain = logins.findColumnByName('domain')!;
+    const domainUnique = domain.clone();
+    domainUnique.isUnique = true;
+    await queryRunner.changeColumn('orgs', domain, domainUnique);
+
+    // On postgres, all of the above amounts to:
+    //   ALTER TABLE "orgs" ADD CONSTRAINT "..." UNIQUE ("domain")
+    // On sqlite, the table gets regenerated.
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<any> {
+    const logins = (await queryRunner.getTable('orgs'))!;
+    const domain = logins.findColumnByName('domain')!;
+    const domainNonUnique = domain.clone();
+    domainNonUnique.isUnique = false;
+    await queryRunner.changeColumn('orgs', domain, domainNonUnique);
+
+    // On postgres, all of the above amount to:
+    //   ALTER TABLE "orgs" DROP CONSTRAINT "..."
+  }
+}