Bug fix: affected packages not correctly detected
    
    When the affected packages are modular RPMs, sfm2 uses a different
    format: `module_name:module_stream:affected_package_name` while normally
    it is simply `affected_package_name`. With this patch we enhance
    Freshmaker to compare differently this when it is for a modular RPM.
    
    ref: CLOUDWF-1038
    
    Signed-off-by: Giulia Naponiello <gnaponie@redhat.com>