Give route-proxy its state on the bus and three tools, so a site's route, certificate and last answer are read from the mesh instead of with curl (issue 774)

The web front kept nothing on the bus: whether grafana or drive was routed, where to, with which
certificate, and what it last answered could only be learned with curl or the container's log.

The proxy now keeps `routes` and `unrouted` (announced readable, keyed <node>.<name>), written on
change by one writer: route set changes, certificates stored by autocert's cache or failing at a
handshake, upstream answers that differ from the last written (or are a minute old), and names
refused in a request or a handshake. The provider helper's bundle serves route_proxy_routes,
route_proxy_route and route_proxy_unrouted from those states.

Quick: log the routes at start and grep the journal. Thorough: the state on the bus and the tools
that read it, mesh-wide, in one call. Chose thorough: the operator's question is mesh-wide and
recurs, and the log says nothing about certificates or answers.

Tests: two table tests added (the ledger, the tools), both failing without the change; four
authority tests and four skipped-route tests merged into two, so the module has four fewer.

modules/route-proxy/module.json

@@ -244,8 +244,29 @@
     }
   ],
   "state": [
-    "bound"
+    "bound",
+    "routes",
+    {
+      "name": "unrouted",
+      "ttl-seconds": 604800
+    }
   ],
+  "tools": [
+    "route_proxy_routes",
+    "route_proxy_route",
+    "route_proxy_unrouted"
+  ],
+  "replaces": {
+    "route_proxy_routes": [
+      "curl -I"
+    ],
+    "route_proxy_route": [
+      "openssl s_client -connect"
+    ],
+    "route_proxy_unrouted": [
+      "docker logs route-proxy"
+    ]
+  },
   "reads": [
     "mesh-controller.assignments"
   ]