State each provision's identity bound (hq issue 263)

Consumers were held to an S3 access key's 20 characters whatever they
required. Each provider now says what its backend keeps: minio 20,
PostgreSQL and MongoDB and DNS 63, Gitea 40, a mailbox 64, SQL Server 128,
Keycloak 255, unbounded where the store has no limit, and none for the
resolver and route provisions, which keep no name of their consumers.
Needs the controller that reads the field (mesh-controller, ADR 0225).

modules/route-proxy/module.json

@@ -8,7 +8,8 @@
   "provides": [
     {
       "name": "route",
-      "scope": "mesh"
+      "scope": "mesh",
+      "identity": false
     }
   ],
   "serves": {