Add country_code attribute to Security model and related classes

* Update Security model to include country_code in the data definition.
* Modify Provider::SecurityConcept to define country_code for security.
* Enhance Provider::Synth to extract country_code from security data.
* Update Security::Provided to include country_code when creating security instances.
* Adjust Security::SynthComboboxOption to add country_code as an attribute.
* Revise combobox_security partial to conditionally display country flag and code.

app/models/security/provided.rb

@@ -22,6 +22,7 @@ module Security::Provided
             name: provider_security.name,
             logo_url: provider_security.logo_url,
             exchange_operating_mic: provider_security.exchange_operating_mic,
+            country_code: provider_security.country_code
           )
         end
       else