In some cases, it may be necessary to create a filesystem with specific features
enabled/disabled.
This PR makes it possible to create filesystems this way. It does so
by introducing a new m_Features member variable and the createWithFeatures()
function to the FileSystem base class. The latter function is implemented
for the btrfs, ext2/3/4 and FAT filesystems.
Additionnally, the CreateFileSystemJob has been modified to enable
creating/formatting filesystems with specific features enabled.
Differential Revision: https://phabricator.kde.org/D21903
CCBUG: 342178
Arnaud Ferraris