Add the ability to generate a playwright/cypress e2e companion app

[astanb]

If I generate a react application, for example my-app, I get offered the option to generate a my-app-e2e app alongside it. If I decline and later on want to add that e2e app, I can't seem to do it. The NX Playwright generator (and apparently Cypress too) only supports adding an e2e folder and configuration to an existing app, but does not support generating a new my-app-e2e app.