Put all KMyMoney config files in kmymoney subdirectory

KMyMoney configuration files are scattered in ~/.config. This patch puts
them all in ~/.config/kmymoney for easier backup and potential name
clash avoidance with other apps plugins.
Besides it allows migration of more configuration files from KDE 4.
It's also a good moment to rename "Print Check" to "Check printing" as I
think is better name in English and Walmart has service by that name :)

Differential Revision: https://phabricator.kde.org/D9592