Add resolution manager and unsupported flags (#2124)

* Add unsupported reason flags

* Restore test_network.py

* Add Resolution manager object

* fix import

tests/api/test_resolution.py

@@ -0,0 +1,13 @@
+"""Test Resolution API."""
+import pytest
+
+from supervisor.const import ATTR_UNSUPPORTED, UnsupportedReason
+
+
+@pytest.mark.asyncio
+async def test_api_resolution_base(coresys, api_client):
+    """Test resolution manager api."""
+    coresys.resolution.unsupported = UnsupportedReason.OS
+    resp = await api_client.get("/resolution")
+    result = await resp.json()
+    assert UnsupportedReason.OS in result["data"][ATTR_UNSUPPORTED]