Use the features of ransack to filter in the database
Use the features of ransack to filter in the database

Instead of loading all the models into memory. This should make
search more performant now that we have several thousand certificates.
theodi/open-data-certificate,istvan-antal/open-data-certificate,ahmadassaf/open-data-certificate,theodi/open-data-certificate,zoul/open-data-certificate,zoul/open-data-certificate,istvan-antal/open-data-certificate,theodi/open-data-certificate,Motejl/open-data-certificate,ahmadassaf/open-data-certificate,ahmadassaf/open-data-certificate,istvan-antal/open-data-certificate,Motejl/open-data-certificate,zoul/open-data-certificate,zoul/open-data-certificate,Motejl/open-data-certificate,Motejl/open-data-certificate,ahmadassaf/open-data-certificate,theodi/open-data-certificate