to make it possible to generate two columns with UUID.

```
select generateUUIDv4(1), generateUUIDv4(2);

┌─generateUUIDv4(1)────────────────────┬─generateUUIDv4(2)────────────────────┐
│ bc834744-236b-4860-a961-4f8aafcae2b5 │ 37e7908c-e1d4-491f-b34d-dee0de7794df │
└──────────────────────────────────────┴──────────────────────────────────────┘
```

the same as rand() https://clickhouse.com/docs/en/sql-reference/functions/random-functions#rand

_x — [Expression](https://clickhouse.com/docs/en/sql-reference/syntax#syntax-expressions) resulting in any of the [supported data types](https://clickhouse.com/docs/en/sql-reference/data-types/#data_types). The resulting value is discarded, but the expression itself if used for bypassing [common subexpression elimination](https://clickhouse.com/docs/en/sql-reference/functions/#common-subexpression-elimination) if the function is called multiple times in one query. Optional parameter._


https://github.com/ClickHouse/ClickHouse/issues/37366
#undef DECLARE_SEVERAL_IMPLEMENTATIONS
class FunctionGenerateUUIDv4 : public TargetSpecific::Default::FunctionGenerateUUIDv4
{
public:
    explicit FunctionGenerateUUIDv4(ContextPtr context) : selector(context)
    {
        selector.registerImplementation<TargetArch::Default,
            TargetSpecific::Default::FunctionGenerateUUIDv4>();
    #if USE_MULTITARGET_CODE
        selector.registerImplementation<TargetArch::AVX2,
            TargetSpecific::AVX2::FunctionGenerateUUIDv4>();
    #endif
    }
    ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override
    {
        return selector.selectAndExecute(arguments, result_type, input_rows_count);
    }
    static FunctionPtr create(ContextPtr context)
    {
        return std::make_shared<FunctionGenerateUUIDv4>(context);
    }
private:
    ImplementationSelector<IFunction> selector;
};
void registerFunctionGenerateUUIDv4(FunctionFactory & factory)
{
    factory.registerFunction<FunctionGenerateUUIDv4>();
}
}