Alias unified job template search fields for presentation

The polymorphic accessors have a name that is different than our
normal presentation name for these types. This aliases them for the
presentation layer and then handles processing them when they are
given as filters.

awx/main/tests/functional/api/test_unified_job_template.py

@@ -0,0 +1,11 @@
+import pytest
+
+from django.core.urlresolvers import reverse
+
+
+@pytest.mark.django_db
+def test_aliased_forward_reverse_field_searches(instance, options, get, admin):
+    url = reverse('api:unified_job_template_list')
+    response = options(url, None, admin)
+    assert 'job_template__search' in response.data['related_search_fields']
+    get(reverse("api:unified_job_template_list") + "?job_template__search=anything", user=admin, expect=200)