feat: implement rename table (#802)

* feat: support renaming tables in the mito table engine

* chore: add test for table engine

* chore: fix test

src/api/greptime/v1/ddl.proto

@@ -38,6 +38,7 @@ message AlterExpr {
   oneof kind {
     AddColumns add_columns = 4;
     DropColumns drop_columns = 5;
+    RenameTable rename_table = 6;
   }
 }
 
@@ -60,6 +61,10 @@ message DropColumns {
   repeated DropColumn drop_columns = 1;
 }
 
+message RenameTable {
+  string new_table_name = 1;
+}
+
 message AddColumn {
   ColumnDef column_def = 1;
   bool is_key = 2;