Diagnostics report for Thread networks (#88541)

* Initial diagnostics

* Include MLP of local OTBR

* Add dep on pyroute2

* Move pyroute2 onto executor

* More comments

* Read thread data direct from zeroconf cache

* Get neighbour cache for known BR's

* isort

* mypy

* Add diagnostic test

* rel import

* Fix pylint

* Restore coverage in discovery.py

tests/components/thread/test_websocket_api.py

@@ -240,6 +240,8 @@ async def test_discover_routers(
                 "network_name": "OpenThread HC",
                 "server": "core-silabs-multiprotocol.local.",
                 "vendor_name": "HomeAssistant",
+                "addresses": ["192.168.0.115"],
+                "thread_version": "1.3.0",
             },
             "key": "aeeb2f594b570bbf",
             "type": "router_discovered",
@@ -265,6 +267,8 @@ async def test_discover_routers(
                 "network_name": "NEST-PAN-E1AF",
                 "server": "2d99f293-cd8e-2770-8dd2-6675de9fa000.local.",
                 "vendor_name": "Google Inc.",
+                "thread_version": "1.3.0",
+                "addresses": ["192.168.0.124"],
             },
             "key": "f6a99b425a67abed",
             "type": "router_discovered",