Some non-database tests are currently accessing the database. Fixing
them means either avoiding the DB access if it's possible and makes
sense for the test, or adding the `Database` group otherwise. In
particular:
- Replace global/static functions with services in a couple places to
make testing easier.
- RevisionRendererTest needs to be in the Database group due to heavy
global state usage (including DB) by Parser
- ActionFactoryIntegrationTest and SpecialPageFatalTest should be in
the database group because they test many different classes, and some
of which may use the database in the tested methods.
- SpecialUserLogoutTest must be in the database group because of User.
- Some pager tests are using wfGetDB directly.
Change-Id: I96eb2acf9a2cbfd17e81225db2773d5e8e30260b
