Support MMRV in patient session pages

This ensures that triage for MMRV is supported. The programme setter has to take into account
the variants instead of just the types of programmes. This hasn't been a problem so far as triage for
verbal consent is built into the consent flow rather than a separate action.

Author: murugapl

app/controllers/patient_sessions/base_controller.rb

@@ -44,15 +44,13 @@ def set_patient_location
   end
 
   def set_programme
-    return unless params.key?(:programme_type) || params.key?(:type)
+    requested_type = params[:programme_type].presence || params[:type].presence
+    return unless requested_type
 
     programme =
       @session
         .programmes_for(patient: @patient)
-        .find do |programme|
-          programme.type == params[:programme_type] ||
-            programme.type == params[:type]
-        end
+        .find { it.variants.any? { |v| v.to_param == requested_type } }
 
     raise ActiveRecord::RecordNotFound if programme.nil?