feat(proxy): add proxy management endpoint and proxy creation API

- Implement new endpoint for creating frpc proxy configurations
- Add DBQueryFrpcInstanceByID function to fetch instances by ID
- Move proxy generation logic to separate function in frpcProxyAct.go
- Update API documentation with new proxy creation endpoint

router.go

@@ -29,4 +29,5 @@ func setupRoutes() {
 	http.HandleFunc("/frpcAct/instanceMgr/delete", DeleteInstanceHandler)
 	http.HandleFunc("/frpcAct/instanceMgr/modify", ModifyInstanceHandler)
 	http.HandleFunc("/frpcAct/instanceMgr/list", ListInstancesHandler)
+	http.HandleFunc("/frpcAct/proxyMgr/create", CreateProxyHandler)
 }