Persist all PDS search results for patient changesets

Previously, only the final PDS search result was persisted for a patient changeset. In-memory updates to `patient_changeset.search_results` will be lost between job executions if not explicitly saved.

This commit ensures `patient_changeset.search_results` is saved after each PDS lookup, preserving the full history of search steps.

Author: murugapl

app/jobs/process_patient_changesets_job.rb

@@ -17,18 +17,15 @@ def perform(patient_changeset, step_name = nil)
       result, pds_patient =
         search_for_patient(patient_changeset.child_attributes, step_name)
       patient_changeset.search_results << {
-        step: step_name,
-        result: result,
+        step: step_name.to_s,
+        result: result.to_s,
         nhs_number: pds_patient&.nhs_number
-      }
-
-      if multiple_nhs_numbers_found?(patient_changeset)
-        finish_processing(patient_changeset)
-      end
+      }.with_indifferent_access
 
       next_step = step[result]
 
-      if result == :error || next_step.nil? || next_step == :give_up
+      if result == :error || next_step.nil? || next_step == :give_up ||
+           multiple_nhs_numbers_found?(patient_changeset)
         finish_processing(patient_changeset)
       elsif next_step == :save_nhs_number_if_unique
         if nhs_number_is_unique_across_searches?(patient_changeset)
@@ -40,9 +37,11 @@ def perform(patient_changeset, step_name = nil)
         end
         finish_processing(patient_changeset)
       elsif next_step.in?(steps.keys)
+        patient_changeset.save!
         raise "Recursive step detected: #{next_step}" if next_step == step_name
         enqueue_next_search(patient_changeset, next_step)
       else
+        patient_changeset.save!
         raise "Unknown step: #{next_step}"
       end
     end