Resolve "Send deployment information in job API"

What does this MR do?

Extend BuildDetailEnity to include a new key deployment_status which has all the information about deployments.

What are the relevant issue numbers?

gitlab-org/gitlab-ce#50460

gitlab-org/gitlab-ce#50101

To Do

• Create issue for environment json schema

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides

Closes #50460 (closed)

app/models/ci/build.rb

@@ -647,6 +647,23 @@ def collect_test_reports!(test_reports)
       end
     end
 
+    # Virtual deployment status for depending on the environment status.
+    def deployment_status
+      return nil unless starts_environment?
+
+      status = 'creating'
+
+      status = 'failed' if complete? && !success?
+
+      if success? && last_deployment.present?
+        status = 'out_of_date'
+
+        status = 'last' if last_deployment.last?
+      end
+
+      status
+    end
+
     private
 
     def each_test_report