feat: add source_tables and source_table_ids (#151)

* feat: add `source_tables`

* feat: use `SchemaScopedTableName`

* chore: include flow proto

* chore: rename

* feat: add `CreateFlowTask` and `DropFlowTask`

src/v1/flow.rs

@@ -0,0 +1,15 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+tonic::include_proto!("greptime.v1.flow");