better encode dict, add $exists to whitelist
better encode dict, add $exists to whitelist

ehealthafrica-ci/formhub,spatialdev/onadata,ultimateprogramer/formhub,awemulya/fieldsight-kobocat,ehealthafrica-ci/onadata,kobotoolbox/kobocat,ehealthafrica-ci/onadata,eHealthAfrica/onadata,ultimateprogramer/formhub,GeoODK/formhub,jomolinare/kobocat,sounay/flaminggo-test,awemulya/fieldsight-kobocat,SEL-Columbia/formhub,makinacorpus/formhub,kobotoolbox/kobocat,piqoni/onadata,SEL-Columbia/formhub,sounay/flaminggo-test,wesley1001/formhub,jomolinare/kobocat,eHealthAfrica/formhub,ehealthafrica-ci/onadata,jomolinare/kobocat,qlands/onadata,spatialdev/onadata,GeoODK/onadata,smn/onadata,SEL-Columbia/formhub,SEL-Columbia/formhub,piqoni/onadata,eHealthAfrica/formhub,wesley1001/formhub,GeoODK/formhub,jomolinare/kobocat,ultimateprogramer/formhub,kobotoolbox/kobocat,smn/onadata,eHealthAfrica/onadata,sounay/flaminggo-test,GeoODK/formhub,mainakibui/kobocat,smn/onadata,ehealthafrica-ci/onadata,piqoni/onadata,awemulya/fieldsight-kobocat,GeoODK/onadata,makinacorpus/formhub,ehealthafrica-ci/formhub,wesley1001/formhub,mainakibui/kobocat,smn/onadata,mainakibui/kobocat,ultimateprogramer/formhub,awemulya/fieldsight-kobocat,GeoODK/onadata,kobotoolbox/kobocat,qlands/onadata,hnjamba/onaclone,hnjamba/onaclone,spatialdev/onadata,piqoni/onadata,qlands/onadata,hnjamba/onaclone,eHealthAfrica/formhub,makinacorpus/formhub,spatialdev/onadata,mainakibui/kobocat,wesley1001/formhub,GeoODK/onadata,makinacorpus/formhub,sounay/flaminggo-test,hnjamba/onaclone,eHealthAfrica/formhub,qlands/onadata,ehealthafrica-ci/formhub,ehealthafrica-ci/formhub,eHealthAfrica/onadata