[Bug](exchange) fix exchange of tablet shuffle send block error

[zhangstar333]

What problem does this PR solve?

Problem Summary:
test case: #44215
the _batching_block is same as block which is used for output.
and maybe different with input block in some column about nullable type.
so if sink this will cause nullable type not equal as origin.

Status VRowDistribution::generate_rows_distribution(
        vectorized::Block& input_block, std::shared_ptr<vectorized::Block>& block,
        int64_t& filtered_rows, bool& has_filtered_rows,
        std::vector<RowPartTabletIds>& row_part_tablet_ids, int64_t& rows_stat_val)
    .......
    // batching block rows which need new partitions. deal together at finish.
    if (!_batching_block) [[unlikely]] {
        std::unique_ptr<Block> tmp_block = block->create_same_struct_block(0);
        _batching_block = MutableBlock::create_unique(std::move(*tmp_block));
    }

void OlapTableBlockConvertor::_convert_to_dest_desc_block(doris::vectorized::Block* block) {
    for (int i = 0; i < _output_tuple_desc->slots().size() && i < block->columns(); ++i) {
        SlotDescriptor* desc = _output_tuple_desc->slots()[i];
        if (desc->is_nullable() != block->get_by_position(i).type->is_nullable()) {
            if (desc->is_nullable()) {
                block->get_by_position(i).type =
                        vectorized::make_nullable(block->get_by_position(i).type);
                block->get_by_position(i).column =
                        vectorized::make_nullable(block->get_by_position(i).column);
            } else {
                block->get_by_position(i).type = assert_cast<const vectorized::DataTypeNullable&>(
                                                         *block->get_by_position(i).type)
                                                         .get_nested_type();
                block->get_by_position(i).column = assert_cast<const vectorized::ColumnNullable&>(
                                                           *block->get_by_position(i).column)
                                                           .get_nested_column_ptr();
            }
        }
    }
}

Release note

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[doris-robot]

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[zhangstar333]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[doris-robot]

TeamCity be ut coverage result:
Function Coverage: 37.97% (9899/26068)
Line Coverage: 29.16% (82730/283663)
Region Coverage: 28.30% (42493/150136)
Branch Coverage: 24.88% (21546/86610)
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[HappenLee]

LGTM

[github-actions]

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

[github-actions]

PR approved by anyone and no changes requested.