rpc: Transform /status result.node_info.other into map (#2417)

* [rpc] transform /status result.node_info.other into map
* amino does not support maps, duh

Refs #2391

docs/spec/p2p/peer.md

@@ -83,7 +83,15 @@ type NodeInfo struct {
   Channels   []int8
 
   Moniker    string
-  Other      []string
+  Other      NodeInfoOther
+}
+
+type NodeInfoOther struct {
+	AminoVersion     string
+	P2PVersion       string
+	ConsensusVersion string
+	RPCVersion       string
+	TxIndex          string
 }
 ```