Handle common argument in aggregate parameter for vyos module (#28182)

* Handle common agrument in aggregate parameter for vyos module

*  Add supoort to set parameter in aggregate to it's respctive
   top level argument if value not provided in aggregate.
*  Aggregate argument spec validation
*  Documentation for aggregate

* Fix unit test failure

lib/ansible/modules/network/interface/net_interface.py

@@ -87,6 +87,24 @@ EXAMPLES = """
     name: ge-0/0/1
     description: test-interface
     enabled: False
+
+- name: Create interface using aggregate
+  net_interface:
+    aggregate:
+      - name: ge-0/0/1
+        description: test-interface-1
+      - name: ge-0/0/2
+        description: test-interface-2
+    speed: 1g
+    duplex: full
+    mtu: 512
+
+- name: Delete interface using aggregate
+  junos_interface:
+    aggregate:
+      - name: ge-0/0/1
+      - name: ge-0/0/2
+    state: absent
 """
 
 RETURN = """