Port AccountsFilterModel away from GroupModelItem
Port AccountsFilterModel away from GroupModelItem

(and disable the filtering for now)

leonhandreke/ktp-common-internals,leonhandreke/ktp-common-internals,KDE/ktp-common-internals,leonhandreke/ktp-common-internals,KDE/ktp-common-internals,KDE/ktp-common-internals