Move Mdm::WebPage cookie spec to proper context
Move Mdm::WebPage cookie spec to proper context

MSP-13193

* Since #cookie is not an association, move it to more suitable context category

bcook-r7/metasploit_data_models,bcook-r7/metasploit_data_models,rapid7/metasploit_data_models,rapid7/metasploit_data_models,rapid7/metasploit_data_models,bcook-r7/metasploit_data_models