feat: table route cache (#462)

* feat: table route cache

Co-authored-by: luofucong <luofucong@greptime.com>

src/common/catalog/src/helper.rs

@@ -118,6 +118,7 @@ pub struct TableGlobalValue {
     pub id: TableId,
     /// Id of datanode that created the global table info kv. only for debugging.
     pub node_id: u64,
+    // TODO(LFC): Maybe remove it?
     /// Allocation of region ids across all datanodes.
     pub regions_id_map: HashMap<u64, Vec<u32>>,
     /// Node id -> region ids