**How to reproduce**
Clickhouse version 20.11.5.18, 20.8.7.15, 20.3.19
```
SELECT
    groupUniqArray(val) AS uniq,
    toTypeName(uniq),
    groupArray(val) AS arr,
    toTypeName(arr)
FROM
(
    SELECT CAST(number % 2, 'Enum(\'hello\' = 1, \'world\' = 0)') AS val
    FROM numbers(2)
)

Query id: d4657f27-c8bd-4174-9947-c6c48d0222d5

┌─uniq──┬─toTypeName(groupUniqArray(val))─┬─arr───────────────┬─toTypeName(groupArray(val))────────────┐
│ [0,1] │ Array(Int8)                     │ ['world','hello'] │ Array(Enum8('world' = 0, 'hello' = 1)) │
└───────┴─────────────────────────────────┴───────────────────┴────────────────────────────────────────┘
```

{
        for (size_t i = 1; i < value.size(); ++i)
        {
            size_t j = genRandom(i + 1);
            std::swap(value[i], value[j]);
        }
    }
};
template <typename T, bool has_sampler>
struct GroupArrayNumericData;
template <typename T>
struct GroupArrayNumericData<T, false>
{
    
    using Allocator = MixedAlignedArenaAllocator<alignof(T), 4096>;
    using Array = PODArray<T, 32, Allocator>;
    Array value;
};
template <typename T>
struct GroupArrayNumericData<T, true> : public GroupArraySamplerData<T>
{
};
template <typename T, typename Trait>
class GroupArrayNumericImpl final