Added function to do get advisories by product and filter get_by_severity and get_by_all with date
Added function to do get advisories by product and filter get_by_severity and get_by_all with date

CiscoPSIRT/openVulnAPI,CiscoPSIRT/openVulnAPI,CiscoPSIRT/openVulnAPI,CiscoPSIRT/openVulnAPI,CiscoPSIRT/openVulnAPI