Add spec for personal namespace project with license

What does this MR do and why?

Describe in detail what your merge request does and why.

Adds feature spec for creating a project in personal namespace with Premium license features available. This is another layer of protection on top of the E2E tests.

Related to production issue: gitlab-com/gl-infra/production#5340 (closed)

And test gap analysis: https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/976

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