(core) Add product for new personal plan

Summary:
Adds the new personal plan as a product that will be available
in the future. Can be enabled along with other plan-related via
an environment variable.

Test Plan: Browser tests and existing tests.

Reviewers: jarek

Reviewed By: jarek

Subscribers: dsagal

Differential Revision: https://phab.getgrist.com/D3533

test/nbrowser/gristUtils.ts

@@ -2435,10 +2435,6 @@ export async function setWidgetUrl(url: string) {
   await waitForServer();
 }
 
-export async function toggleNewDeal(on = true) {
-  await driver.executeScript(`NEW_DEAL.set(${on ? 'true' : 'false'});`);
-}
-
 } // end of namespace gristUtils
 
 stackWrapOwnMethods(gristUtils);