feat: public contracts for update progress, DNS forwards and OSPF (4.17.0)

An application followed a firewall's upgrade, edited its resolver's
forwards and read its OSPF state through the driver's private REST
helpers (NetOrk/netork#1113). Declared contracts, neutral shapes:

- UpdateMixin.get_update_progress() -> UpdateProgressDict {state, log}
  for an update apply_updates only starts.
- DnsForwardMixin: get_dns_forwards(), set_dns_forward(domain, server,
  port), remove_dns_forward(domain); the driver applies.
- OspfMixin.get_ospf() -> OspfDict {router_id, areas, interfaces}; the
  routing daemon's format is the driver's to translate.

All declared only.

tests/test_public_contracts_1113.py

@@ -0,0 +1,47 @@
+"""Public contracts for what an application reached through driver internals.
+
+netOrk followed a firewall's upgrade, edited its resolver's forwards and read
+its OSPF state through the driver's private REST helpers (NetOrk/netork#1113).
+Each becomes a declared method with a neutral shape; the vendor's own format
+is translated by the driver.
+"""
+
+from __future__ import annotations
+
+from typing import get_type_hints
+
+from napalm_device_types import (
+    DnsForwardDict,
+    DnsForwardMixin,
+    OspfDict,
+    OspfInterfaceDict,
+    OspfMixin,
+    UpdateMixin,
+    UpdateProgressDict,
+)
+
+
+def test_update_progress_is_a_state_and_its_log():
+    assert set(get_type_hints(UpdateProgressDict)) == {"state", "log"}
+    assert not hasattr(UpdateMixin, "get_update_progress")
+
+
+def test_a_dns_forward_names_the_domain_and_where_it_goes():
+    assert set(get_type_hints(DnsForwardDict)) == {"domain", "server", "port", "enabled"}
+    for name in ("get_dns_forwards", "set_dns_forward", "remove_dns_forward"):
+        assert not hasattr(DnsForwardMixin, name), name
+
+
+def test_ospf_in_neutral_terms():
+    assert set(get_type_hints(OspfDict)) == {"router_id", "areas", "interfaces"}
+    assert set(get_type_hints(OspfInterfaceDict)) == {
+        "address",
+        "prefix_length",
+        "area",
+        "network_type",
+        "authentication",
+        "neighbors",
+        "neighbors_adjacent",
+        "cost",
+    }
+    assert not hasattr(OspfMixin, "get_ospf")