Adding asdot notation to ASN views

Adds custom property to asn model to compute asdot notation if required.
Updates asn view to show asdot notation if one exists in the format xxxxx (yyy.yyy)
Adds a custom column renderer to asn table to display asdot notation if one exists

netbox/ipam/tables/ip.py

@@ -106,6 +106,13 @@ class ASNTable(BaseTable):
     asn = tables.Column(
         linkify=True
     )
+
+    def render_asn(self, value, record):
+        if record.asdot_notation:
+            return f'{value} ({record.asdot_notation})'
+        else:
+            return value
+
     site_count = LinkedCountColumn(
         viewname='dcim:site_list',
         url_params={'asn_id': 'pk'},