**Describe the bug**
Under certain conditions the equals comparison between String and Date yields the wrong result. Range Comparisons with greather-than-equals returns the correct result set.

**How to reproduce**
* Which ClickHouse server version to use: 21.2.5.5 (latest at the time of this issue)
* Which interface to use, if matters: HTTP (but should not matter)

```sql
CREATE TABLE default.myTable (
	myDay Date,
	myOrder Int32,
	someData String
) 
ENGINE = ReplacingMergeTree
PARTITION BY floor(toYYYYMMDD(myDay), -1)
ORDER BY (myOrder)
;

INSERT INTO default.myTable (myDay, myOrder) VALUES ('2021-01-01', 1);
INSERT INTO default.myTable (myDay, myOrder) VALUES ('2021-01-02', 2); // This row should be returned
INSERT INTO default.myTable (myDay, myOrder) VALUES ('2021-01-03', 3);

SELECT * FROM default.myTable mt
WHERE myDay = '2021-01-02';
```

**Expected behavior**
The last query in the example should yield the marked row. Instead it returns a empty result set.

There must be a connection to the used `PARTITION KEY`. The issue fails to reproduce as soon as I do any changes to the `PARTITION KEY` setting.

: func->getMonotonicityForRange(*current_type.get(), key_range.left, key_range.right);
        if (!monotonicity.is_monotonic)
        {
            return {};
        }
        
        
        
        if (!key_range.left.isNull())
        {
            key_range.left = applyFunction(func, current_type, key_range.left);
            key_range.left_included = true;
        }
        if (!key_range.right.isNull())
        {
            key_range.right = applyFunction(func, current_type, key_range.right);
            key_range.right_included = true;
        }
        current_type = func->getResultType();
        if (!monotonicity.is_positive)
            key_range.swapLeftAndRight();
    }
    return key_range;
}
bool KeyCondition::matchesExactContinuousRange() const
{
    
    if (hasMonotonicFunctionsChain())
        return false;
    enum Constraint