MessageFactoryTest: fix inconsistencies, use fake XDG dirs and KDEHOME
The test uses KIdentityManagement::IdentityManager, so when run on local machine it reads and writes into user's identities. This change forces fake XDG dirs to make sure we don't touch user's stuff. Fake KDEHOME is needed to prevent config migration from user's KDEHOME into the fake XDG dirs. Also replaces some QVERIFYies with QCOMPAREs and adapts testCreateForward() test to match with minor behaviour change in KMime and/or composer.
Showing with 21 additions and 13 deletions