updated the way filters are defined, fixed some null value issues
updated the way filters are defined, fixed some null value issues

WNPRC-EHR-Services/wnprc-modules,WNPRC-EHR-Services/wnprc-modules,WNPRC-EHR-Services/wnprc-modules,WNPRC-EHR-Services/wnprc-modules,WNPRC-EHR-Services/wnprc-modules,WNPRC-EHR-Services/wnprc-modules,WNPRC-EHR-Services/wnprc-modules