Improve consistency displaying "Test Transactions"
There are currently a number of inconsistencies with displaying test transactions:
- There is either no indication, or it is not obvious that you are viewing a test contribution/recur/membership when viewing the details.
- Test memberships do not appear in the contact membership tab, but test contributions/recurring contributions do.
- Add some "help" text that appears above the entity detail when viewing the entity if it is a test transaction.
- Show test memberships in contact membership tab so it is consistent with other tabs.