tests:add topotest for EVPN aggregate prefix route

tests:add topotest for EVPN aggregate prefix route

Toptotest covers to aggregate EVPN prefix routes.

Testing:

tests/topotests/bgp_evpn_vxlan_svd_topo1$ sudo -E python3 -m pytest -s -vv --cli-on-error
PASSED
test_bgp_evpn_vxlan_svd.py::test_pe_advertise_aggr_evpn_route
--------------------- live log call -------------------------------
2024-03-04 19:59:45,340 INFO: P1: checking if daemons are running
2024-03-04 19:59:45,444 INFO: PE1: checking if daemons are running
2024-03-04 19:59:45,578 INFO: PE2: checking if daemons are running
2024-03-04 19:59:45,680 INFO: host1: checking if daemons are running
2024-03-04 19:59:45,798 INFO: host2: checking if daemons are running
2024-03-04 19:59:45,896 INFO: topo: Checking BGP EVPN route contains non-aggregate prefixes
2024-03-04 19:59:45,992 INFO: topo: Configure BGP aggregate-address summary-only under ipv4-unicast
2024-03-04 19:59:46,120 INFO: topo: Checking BGP EVPN route contains aggregated prefix
PASSED

------- generated xml file: /tmp/topotests/topotests.xml -----
======= 10 passed, 1 skipped in 47.95s =====

Signed-off-by: Chirag Shah <chirag@nvidia.com>