EmptyState - enhance autofixer for when titleText and children are not present

[thatblindgeye]

Followup to #749. One of the issues found was that if there's no titleText or children for EmptyStateHeader, the autofixer we currently have doesn't run. We can try to provide an autofixer in this instance (the workaround consumer-side was passing titleText="" to EmptyState, which may not be ideal if we want to encourage consumers to pass a valid titleText).

[kmcfaul]

Update the current EmptyState codemod to adjust for not requiring titleText anymore