enh: add command show vnodes on dnode <dnode_id>

source/libs/parser/inc/sql.y

@@ -475,8 +475,8 @@ cmd ::= SHOW TAGS FROM table_name_cond(A) from_db_opt(B).
 cmd ::= SHOW TAGS FROM db_name(B) NK_DOT table_name(A).                           { pCxt->pRootNode = createShowStmtWithCond(pCxt, QUERY_NODE_SHOW_TAGS_STMT, createIdentifierValueNode(pCxt, &B), createIdentifierValueNode(pCxt, &A), OP_TYPE_EQUAL); }
 cmd ::= SHOW TABLE TAGS tag_list_opt(C) FROM table_name_cond(A) from_db_opt(B).   { pCxt->pRootNode = createShowTableTagsStmt(pCxt, A, B, C); }
 cmd ::= SHOW TABLE TAGS tag_list_opt(C) FROM db_name(B) NK_DOT table_name(A).     { pCxt->pRootNode = createShowTableTagsStmt(pCxt, createIdentifierValueNode(pCxt, &A), createIdentifierValueNode(pCxt, &B), C); }
-cmd ::= SHOW VNODES NK_INTEGER(A).                                                { pCxt->pRootNode = createShowVnodesStmt(pCxt, createValueNode(pCxt, TSDB_DATA_TYPE_BIGINT, &A), NULL); }
-cmd ::= SHOW VNODES NK_STRING(A).                                                 { pCxt->pRootNode = createShowVnodesStmt(pCxt, NULL, createValueNode(pCxt, TSDB_DATA_TYPE_VARCHAR, &A)); }
+cmd ::= SHOW VNODES ON DNODE NK_INTEGER(A).                                       { pCxt->pRootNode = createShowVnodesStmt(pCxt, createValueNode(pCxt, TSDB_DATA_TYPE_BIGINT, &A), NULL); }
+cmd ::= SHOW VNODES ON DNODE NK_STRING(A).                                        { pCxt->pRootNode = createShowVnodesStmt(pCxt, NULL, createValueNode(pCxt, TSDB_DATA_TYPE_VARCHAR, &A)); }
 // show alive
 cmd ::= SHOW db_name_cond_opt(A) ALIVE.                                           { pCxt->pRootNode = createShowAliveStmt(pCxt, A,    QUERY_NODE_SHOW_DB_ALIVE_STMT); }
 cmd ::= SHOW CLUSTER ALIVE.                                                       { pCxt->pRootNode = createShowAliveStmt(pCxt, NULL, QUERY_NODE_SHOW_CLUSTER_ALIVE_STMT); }