refactor: remove task suffix (#162)

* refactor: remove task suffix

* chore: rename task_options to flow_options

proto/greptime/v1/ddl.proto

@@ -33,15 +33,15 @@ message DdlRequest {
     AlterExpr alter = 3;
     DropTableExpr drop_table = 4;
     TruncateTableExpr truncate_table = 7;
-    CreateFlowTaskExpr create_flow_task = 8;
-    DropFlowTaskExpr drop_flow_task = 9;
+    CreateFlowExpr create_flow = 8;
+    DropFlowExpr drop_flow = 9;
   }
 }
 
-// Create a flow task to run the SQL when new data arrives.
-message CreateFlowTaskExpr {
+// Create a flow to run the SQL when new data arrives.
+message CreateFlowExpr {
   string catalog_name = 1;
-  string task_name = 2;
+  string flow_name = 2;
   repeated TableName source_table_names = 3;
   TableName sink_table_name = 4;
   bool or_replace = 5;
@@ -49,13 +49,13 @@ message CreateFlowTaskExpr {
   string expire_when = 7;
   string comment = 8;
   string sql = 9;
-  map<string, string> task_options = 10;
+  map<string, string> flow_options = 10;
 }
 
-// Remove a flow task.
-message DropFlowTaskExpr {
+// Drop a flow.
+message DropFlowExpr {
   string catalog_name = 1;
-  string task_name = 2;
+  string flow_name = 2;
 }
 
 message CreateTableExpr {

proto/greptime/v1/flow/server.proto

@@ -43,7 +43,7 @@ message InsertRequest {
 message FlowRequest {
   oneof body {
     CreateRequest create = 1;
-    RemoveRequest remove = 2;
+    DropRequest drop = 2;
   }
 }
 
@@ -55,21 +55,21 @@ message FlowResponse {
   repeated TaskId affected_tasks = 4;
 }
 
-// Create a flow task
+// Create a flow
 // 
 // Very similar to `ddl.CreateTaskExpr`, 
 // replace `source_table_names` with `source_table_ids`
 message CreateRequest {
-  TaskId task_id = 1; 
+  TaskId flow_id = 1; 
   repeated TableId source_table_ids = 2;
   TableName sink_table_name = 3;
   bool create_if_not_exists = 4;
   string expire_when = 5;
   string comment = 6;
   string sql = 7;
-  map<string, string> task_options = 8;
+  map<string, string> flow_options = 8;
 }
 
-message RemoveRequest { TaskId task_id = 1; }
+message DropRequest { TaskId flow_id = 1; }
 
 message TaskId { uint32 id = 1; }

proto/greptime/v1/meta/ddl.proto

@@ -60,11 +60,11 @@ message DropDatabaseTask {
 }
 
 message CreateFlowTask {
-    CreateFlowTaskExpr create_flow_task = 1;
+    CreateFlowExpr create_flow = 1;
 }
 
 message DropFlowTask {
-    DropFlowTaskExpr drop_flow_task = 1;
+    DropFlowExpr drop_flow = 1;
 }
 
 message DdlTaskRequest {