(core) Adding fixSiteProducts that changes orgs from teamFree to Free product if it was set be default

Summary:
After release on 2024-06-12 (1.1.15) the GRIST_DEFAULT_PRODUCT env variable wasn't respected by the
method that started the server in single org mode. In all deployments (apart from saas), the default product
used for new sites is set to `Free`, but the code that starts the server enforced `teamFree` product.

This change adds a fix routine that fixes this issue by rewriting team sites from `teamFree` product to `Free`
product only if:
- The default product is set to `Free`
- The deployment type is something other then 'saas'.

Additionally there is a test that will fail after 2024.10.01, as this fix should be removed before this date.

Test Plan: Added test

Reviewers: paulfitz

Reviewed By: paulfitz

Subscribers: paulfitz

Differential Revision: https://phab.getgrist.com/D4272

stubs/app/server/server.ts

@@ -7,6 +7,7 @@
 import {commonUrls} from 'app/common/gristUrls';
 import {isAffirmative} from 'app/common/gutil';
 import {HomeDBManager} from 'app/gen-server/lib/HomeDBManager';
+import {fixSiteProducts} from 'app/gen-server/lib/Housekeeper';
 
 const debugging = isAffirmative(process.env.DEBUG) || isAffirmative(process.env.VERBOSE);
 
@@ -135,6 +136,13 @@ export async function main() {
   if (process.env.GRIST_SERVE_PLUGINS_PORT) {
     await server.startCopy('pluginServer', parseInt(process.env.GRIST_SERVE_PLUGINS_PORT, 10));
   }
+
+  await fixSiteProducts({
+    deploymentType: server.getDeploymentType(),
+    db: server.getHomeDBManager(),
+    dry: true
+  });
+
   return server;
 }