Archives: Solve the 'QCoreApplication::applicationDirPath: Please instantiate the QApplication object first' error

Solve the «QCoreApplication::applicationDirPath: Please instantiate the QApplication object first» error, what required moving code.

Besides, after the code of the `generateKrarcArchiveMimetypes()` function was moved to a constructor, that code is executed only once and the source code ends up being simplified. Make the KrServices class simpler by moving archive-related code to an archive-related class.

Test plan: The one described in the task [Solve some bugs related to archives, remove some duplicated code](https://phabricator.kde.org/T12876).

FIXED: [ 417107 ] QCoreApplication::applicationDirPath: Please instantiate the QApplication object first
BUG: 417107

Differential Revision: https://phabricator.kde.org/D28413