feat (api particulier): add Pole emploi field

app/models/champs/pole_emploi_champ.rb

@@ -0,0 +1,47 @@
+# == Schema Information
+#
+# Table name: champs
+#
+#  id                             :integer          not null, primary key
+#  data                           :jsonb
+#  fetch_external_data_exceptions :string           is an Array
+#  private                        :boolean          default(FALSE), not null
+#  rebased_at                     :datetime
+#  row                            :integer
+#  type                           :string
+#  value                          :string
+#  value_json                     :jsonb
+#  created_at                     :datetime
+#  updated_at                     :datetime
+#  dossier_id                     :integer
+#  etablissement_id               :integer
+#  external_id                    :string
+#  parent_id                      :bigint
+#  type_de_champ_id               :integer
+#
+class Champs::PoleEmploiChamp < Champs::TextChamp
+  # see https://github.com/betagouv/api-particulier/blob/master/src/presentation/middlewares/pole-emploi-input-validation.middleware.ts
+  store_accessor :value_json, :identifiant
+
+  def blank?
+    external_id.nil?
+  end
+
+  def fetch_external_data?
+    true
+  end
+
+  def fetch_external_data
+    return if !valid?
+
+    APIParticulier::PoleEmploiAdapter.new(
+      procedure.api_particulier_token,
+      identifiant,
+      procedure.api_particulier_sources
+    ).to_params
+  end
+
+  def external_id
+    { identifiant: identifiant }.to_json if identifiant.present?
+  end
+end