Add vyos_linkagg module (#26418)

* Add vyos_linkagg module

* Add vyos_linkagg integration tests

* Fix pep8 issue

* Address several review comments

test/integration/targets/vyos_linkagg/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

test/integration/targets/vyos_linkagg/tasks/main.yaml

@@ -0,0 +1,2 @@
+---
+- { include: cli.yaml, tags: ['cli'] }