Make it possible to show corretly if the localstore job is running.
Summary:
Otherwise you see key details are requested the whole time.
test is we there are valid keydata in the mime content.
hasKey is not used anymore
always show keydetails from mimepart
show if key is unknown.
add test for showSignuatureDetails
Subscribers: KDE PIM
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D8949