[fix](insert) fix memory leak for insert transaction

[liaoxin01]

Proposed changes

Issue Number: close #xxx

Problem summary

void CsvReader::_split_line(const Slice& line) {
_split_values.clear();
if (_file_format_type == TFileFormatType::FORMAT_PROTO) {
PDataRow** ptr = reinterpret_cast<PDataRow**>(line.data);
PDataRow* row = *ptr;
for (const PDataColumn& col : (row)->col()) {
int len = col.value().size();
uint8_t* buf = new uint8_t[len];
memcpy(buf, col.value().c_str(), len);
_split_values.emplace_back(buf, len);
}
delete row;
delete[] ptr;
} ...
}

PInternalServiceImpl::send_data(google::protobuf::RpcController* controller,
const PSendDataRequest* request, PSendDataResult* response,
google::protobuf::Closure* done) {
brpc::ClosureGuard closure_guard(done);
TUniqueId fragment_instance_id;
fragment_instance_id.hi = request->fragment_instance_id().hi();
fragment_instance_id.lo = request->fragment_instance_id().lo();
auto pipe = _exec_env->fragment_mgr()->get_pipe(fragment_instance_id);
if (pipe == nullptr) {
response->mutable_status()->set_status_code(1);
response->mutable_status()->add_error_msgs("pipe is null");
} else {
for (int i = 0; i < request->data_size(); ++i) {
PDataRow* row = new PDataRow();
row->CopyFrom(request->data(i));
pipe->append_and_flush(reinterpret_cast<char*>(&row), sizeof(row),
sizeof(row) + row->ByteSizeLong());
}
response->mutable_status()->set_status_code(0);
}
}

There are two problems when using begin, insert into, and commit operations.

1. The memory of buf(uint8_t* buf = new uint8_t[len]) in _split_line function didn't be released when clear _split_values.
2. The memory of PDataRow may leak when the load fails. The memory of row(PDataRow* row = new PDataRow()) in the send_data function can't be released when some error occurs.

Checklist(Required)

• Does it affect the original behavior
• Has unit tests been added
• Has document been added or modified
• Does it need to update dependencies
• Is this PR support rollback (If NO, please explain WHY)

Further comments

If this is a relatively large or complex change, kick off the discussion at dev@doris.apache.org by explaining why you chose the solution you did and what alternatives you considered, etc...

[morningman]

LGTM

[github-actions]

PR approved by at least one committer and no changes requested.

[github-actions]

PR approved by anyone and no changes requested.