Integration Tests only: nxos_udld, nxos_udld_interface, nxos_vxlan_vtep_vni (#29143)

* it cases for vxlan_vtep_vni, udld

* platform specific testing

* fix vxlan_vtep for n7k

* fix udld_intf setup

* skip udld tests on titanium n7k

* remove hardcoding

* fix udld tests for titanium

test/integration/targets/nxos_udld_interface/tasks/cli.yaml

@@ -0,0 +1,15 @@
+---
+- name: collect all cli test cases
+  find:
+    paths: "{{ role_path }}/tests/cli"
+    patterns: "{{ testcase }}.yaml"
+  register: test_cases
+
+- name: set test_items
+  set_fact: test_items="{{ test_cases.files | map(attribute='path') | list }}"
+
+- name: run test case
+  include: "{{ test_case_to_run }}"
+  with_items: "{{ test_items }}"
+  loop_control:
+    loop_var: test_case_to_run