arrow::compute::concat panics for dense union arrays with non-trivial type IDs

[kawadakk]

Describe the bug
arrow::compute::concat panics when called with dense union arrays with type IDs that don't start at zero.

thread 'proptest::tests::qc_row' panicked at 'index out of bounds: the len is 1 but the index is 35', ...\.cargo\registry\src\index.crates.io-6f17d22bba15001f\arrow-data-43.0.0\src\transform\union.rs:53:39
stack backtrace:
 ...
   3: arrow_data::transform::union::build_extend_dense::{{closure}}::{{closure}}
   4: core::iter::traits::iterator::Iterator::for_each::call::{{closure}}
             at /rustc/864bdf7843e1ceabc824ed86d97006acad6af643\library\core\src\iter\traits/iterator.rs:853:29
   5: core::iter::traits::iterator::Iterator::fold
             at /rustc/864bdf7843e1ceabc824ed86d97006acad6af643\library\core\src\iter\traits/iterator.rs:2481:21
   6: core::iter::traits::iterator::Iterator::for_each
             at /rustc/864bdf7843e1ceabc824ed86d97006acad6af643\library\core\src\iter\traits/iterator.rs:856:9
   7: arrow_data::transform::union::build_extend_dense::{{closure}}
             at ...\.cargo\registry\src\index.crates.io-6f17d22bba15001f\arrow-data-43.0.0\src\transform\union.rs:50:13
   8: <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call
             at /rustc/864bdf7843e1ceabc824ed86d97006acad6af643\library\alloc\src/boxed.rs:2021:9
   9: arrow_data::transform::MutableArrayData::extend
             at ...\.cargo\registry\src\index.crates.io-6f17d22bba15001f\arrow-data-43.0.0\src\transform\mod.rs:631:9
  10: arrow_select::concat::concat
             at ...\.cargo\registry\src\index.crates.io-6f17d22bba15001f\arrow-select-43.0.0\src\concat.rs:89:9

To Reproduce

Call arrow::compute::concat and pass the following arrays:

[
    UnionArray(Dense)
    [
        -- type id buffer:
        ScalarBuffer([35])
        -- offsets buffer:
        ScalarBuffer([0])
        -- child 35: "" (Null)
        NullArray(1)
    ],
    UnionArray(Dense)
    [
        -- type id buffer:
        ScalarBuffer([35])
        -- offsets buffer:
        ScalarBuffer([0])
        -- child 35: "" (Null)
        NullArray(1)
    ],
]

of the following data type:

Union(
    [
        (
            35,
            Field {
                name: "",
                data_type: Null,
                nullable: false,
                dict_id: 0,
                dict_is_ordered: false,
                metadata: {},
            },
        ),
    ],
    Dense,
)

Expected behavior

Producing the following array:

UnionArray(Dense)
[
    -- type id buffer:
    ScalarBuffer([35, 35])
    -- offsets buffer:
    ScalarBuffer([0, 1])
    -- child 35: "" (Null)
    NullArray(2)
]

Additional context

[tustvold]

MutableArrayData likely needs to be updated to properly understand UnionArray with non-trivial type ids

[tustvold]

label_issue.py automatically added labels {'arrow'} from #4598