[Spark load][Fe 2/5] Update push task thrift interface (#3718)

1. Add TBrokerScanRange and TDescriptorTable used by ParquetScanner
2. Add new TPushType LOAD_V2 for spark load

gensrc/thrift/AgentService.thrift

@@ -21,6 +21,7 @@ namespace java org.apache.doris.thrift
 include "Status.thrift"
 include "Types.thrift"
 include "PaloInternalService.thrift"
+include "PlanNodes.thrift"
 include "Descriptors.thrift"
 include "Exprs.thrift"
 
@@ -127,6 +128,9 @@ struct TPushReq {
     // fe should inform be that this request is running during schema change
     // be should write two files
     13: optional bool is_schema_changing
+    // 14 and 15 are used by spark load
+    14: optional PlanNodes.TBrokerScanRange broker_scan_range
+    15: optional Descriptors.TDescriptorTable desc_tbl
 }
 
 struct TCloneReq {

gensrc/thrift/Types.thrift

@@ -138,7 +138,9 @@ enum TAggregationType {
 enum TPushType {
     LOAD,
     DELETE,
-    LOAD_DELETE
+    LOAD_DELETE,
+    // for spark load push request
+    LOAD_V2
 }
 
 enum TTaskType {