Now it support only `String` and `FixedString`

https://github.com/ClickHouse/ClickHouse/blob/33aefa832b3c544934a757cc9d0e284252a1dd3e/src/Storages/MergeTree/MergeTreeIndexFullText.cpp#L809

Seems that `LowCardinality(String)` can be supported too, because we only use `column->getDataAt` to retrieve data and it will work on `LowCardinality(String)` in same way as for `String`
https://github.com/ClickHouse/ClickHouse/blob/33aefa832b3c544934a757cc9d0e284252a1dd3e/src/Storages/MergeTree/MergeTreeIndexFullText.cpp#L543
https://github.com/ClickHouse/ClickHouse/blob/33aefa832b3c544934a757cc9d0e284252a1dd3e/src/Storages/MergeTree/MergeTreeIndexFullText.cpp#L145
|| element.function == RPNElement::FUNCTION_NOT_IN
             || element.function == RPNElement::FUNCTION_MULTI_SEARCH
             || element.function == RPNElement::ALWAYS_FALSE)
        {
            rpn_stack.push_back(false);
        }
        else if (element.function == RPNElement::FUNCTION_NOT)
        {
            
        }
        else if (element.function == RPNElement::FUNCTION_AND)
        {
            auto arg1 = rpn_stack.back();
            rpn_stack.pop_back();
            auto arg2 = rpn_stack.back();
            rpn_stack.back() = arg1 && arg2;
        }
        else if (element.function == RPNElement::FUNCTION_OR)
        {
            auto arg1 = rpn_stack.back();
            rpn_stack.pop_back();
            auto arg2 = rpn_stack.back();
            rpn_stack.back() = arg1 || arg2;
        }
        else
            throw Exception("Unexpected function type in KeyCondition::RPNElement", ErrorCodes::LOGICAL_ERROR);
    }
    return rpn_stack[0];
}
bool MergeTreeConditionFullText::mayBeTrueOnGranule(MergeTreeIndexGranulePtr idx_granule) const