feat: Add DropTableTask, AlterTableTask (#54)

* feat: use type instead of pb bytes

* feat: add table_info to CreateTableTask

* fix: remove unused fields

* feat: bring create route method back

* feat: add table_id in SubmitDdlTaskResponse

* feat: add drop table task

* feat: add alter table task

* chore: allow large_enum_variant

* chore: apply suggestions from CR

proto/greptime/v1/meta/route.proto

@@ -21,6 +21,8 @@ option go_package = "github.com/GreptimeTeam/greptime-proto/go/greptime/v1/meta"
 import "greptime/v1/meta/common.proto";
 
 service Router {
+  rpc Create(CreateRequest) returns (RouteResponse) {}
+  
   // Fetch routing information for tables. The smallest unit is the complete
   // routing information(all regions) of a table.
   //
@@ -45,6 +47,14 @@ service Router {
   rpc Delete(DeleteRequest) returns (RouteResponse) {}
 }
 
+message CreateRequest {
+  RequestHeader header = 1;
+
+  TableName table_name = 2;
+  repeated Partition partitions = 3;
+  bytes table_info = 4;
+}
+
 message RouteRequest {
   RequestHeader header = 1;