feat(app-server): update remote control APIs for better UX (#22877)

## Why
To help improve `codex remote-control` CLI UX which I plan to do in a
followup, this PR adds `server-name` to the various remote control APIs:
- `remoteControl/enable`
- `remoteControl/disable`
- `remoteControl/status/changed`

Also, add a `remoteControl/status/read` API. This will be helpful in the
Codex App.

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json

@@ -9995,12 +9995,16 @@
         "installationId": {
           "type": "string"
         },
+        "serverName": {
+          "type": "string"
+        },
         "status": {
           "$ref": "#/definitions/RemoteControlConnectionStatus"
         }
       },
       "required": [
         "installationId",
+        "serverName",
         "status"
       ],
       "title": "RemoteControlStatusChangedNotification",