update startingEntitiesCount at beginning of create e2e test

[ruddell]

The startingEntitiesCount is set in the before method at the beginning of the entity E2E test. If the "create entity" test fails after creating an entity, it will retry that specific test. But the before method does not run again (docs), leading to a stale startingEntitiesCount value.

You can see an example of the issue in the CI logs here. You can validate the issue is happening by checking the screenshots uploaded in the artifacts after that CI run (uploaded here for reference: attempt 1, attempt2, attempt3). I'm not sure why the first attempt failed, but the second and third attempts should be fixed by this PR.

---

Please make sure the below checklist is followed for Pull Requests.

• All continuous integration tests are green
• Tests are added where necessary
• jhipster-online was updated if necessary
• Documentation is added/updated where necessary
• Coding Rules & Commit Guidelines as per our CONTRIBUTING.md document are followed

[mshima]

This should fix the flakiness.
'startingEntitiesCount' should not be at describe scope, it should be a local variable for each test.
This breaks https://docs.cypress.io/guides/references/best-practices.html#Having-tests-rely-on-the-state-of-previous-tests.

Good catch.

[mshima]

This change is required.