Parse user fields where namespace declarations aren't included (#989)

We import XML files that define logs from the previous CORE service. For an unknown reason, some of these files don't include the required namespace declarations to parse `user` values. Instead of changing the source, this change introduces a new method that forces the namespace declaration for user fields.

app/services/imports/user_import_service.rb

@@ -45,7 +45,7 @@ module Imports
     end
 
     def user_field_value(xml_document, field)
-      field_value(xml_document, "user", field)
+      field_value(xml_document, "user", field, { "user" => "dclg:user" })
     end
 
     def role(field_value)

spec/fixtures/imports/user/80d9b73aa1c88b6e5c36ee49be9050b923b4a1bb.xml

@@ -0,0 +1,19 @@
+<user xmlns="dclg:user">
+  <id>80d9b73aa1c88b6e5c36ee49be9050b923b4a1bb</id>
+  <user-name>Jane Doe</user-name>
+  <institution>7c5bd5fb549c09a2c55d7cb90d7ba84927e64618</institution>
+  <user-stamp>1158 1158</user-stamp>
+  <active>true</active>
+  <user-type>Data Provider</user-type>
+  <association-site-id />
+  <e-core-download>false</e-core-download>
+  <raw-data-download>false</raw-data-download>
+  <licence>false</licence>
+  <contact-priority-id>None</contact-priority-id>
+  <email>jane.doe@gov.uk</email>
+  <password>REDACTED</password>
+  <full-name>Jane Doe</full-name>
+  <telephone-no>01111 000000</telephone-no>
+  <deleted>false</deleted>
+  <date-deactivated>2021-09-28Z</date-deactivated>
+</user>

spec/services/imports/user_import_service_spec.rb

@@ -107,6 +107,19 @@ RSpec.describe Imports::UserImportService do
       end
     end
 
+    context "when the user does not have namespace bindings" do
+      let(:old_user_id) { "80d9b73aa1c88b6e5c36ee49be9050b923b4a1bb" }
+
+      it "imports them succesfully" do
+        FactoryBot.create(:organisation, old_org_id:)
+        import_service.create_users("user_directory")
+
+        user = LegacyUser.find_by(old_user_id:)&.user
+        expect(user.name).to eq("Jane Doe")
+        expect(user.email).to eq("jane.doe@gov.uk")
+      end
+    end
+
     context "when a user has already been imported with that email" do
       let!(:org) { FactoryBot.create(:organisation, old_org_id:) }
       let!(:user) { FactoryBot.create(:user, :data_provider, organisation: org, email: "john.doe@gov.uk") }