**Use case**

Comparison between DateTime64 and DateTime / Date types is allowed but the behavior is confusing (it looks like used numerical comparison):

* from one side for zero-precision it works as expected (values compared as datetime-based ones): 

```sql
SELECT toTypeName(dt64) AS dt64_typename, dt64 = dt
FROM 
(
    SELECT 
        toDateTime64(toStartOfInterval(now(), toIntervalSecond(1), 'UTC'), 0, 'UTC') AS dt64,
        toStartOfInterval(now(), toIntervalSecond(1), 'UTC') AS dt
)

/*
┌─dt64_typename────────┬─equals(dt64, dt)─┐
│ DateTime64(0, 'UTC') │                1 │
└──────────────────────┴──────────────────┘
*/
```
* from another side for non-zero-precision its behavior is unexpected if not used explicit type conversion:

```sql
SELECT 
    toTypeName(dt64) AS dt64_typename,
    dt64 = dt,
    toDateTime(dt64) = dt,
    dt64 = toDateTime64(dt, 1, 'UTC')
FROM 
(
    SELECT 
        toDateTime64(toStartOfInterval(now(), toIntervalSecond(1), 'UTC'), 1, 'UTC') AS dt64,
        toStartOfInterval(now(), toIntervalSecond(1), 'UTC') AS dt
)
/*
┌─dt64_typename────────┬─equals(dt64, dt)─┬─equals(toDateTime(dt64), dt)─┬─equals(dt64, toDateTime64(dt, 1, 'UTC'))─┐
│ DateTime64(1, 'UTC') │                0 │                            1 │                                        1 │
└──────────────────────┴──────────────────┴──────────────────────────────┴──────────────────────────────────────────┘
*/
```

**Describe the solution you'd like**
I think this comparison either:
- should be not allowed and throw an exception to ask for user uses explicit conversion
- or make valid implicit conversion relying on datetime/date essence of values

{
        const ColumnString * c0_string = checkAndGetColumn<ColumnString>(c0);
        const ColumnString * c1_string = checkAndGetColumn<ColumnString>(c1);
        const ColumnFixedString * c0_fixed_string = checkAndGetColumn<ColumnFixedString>(c0);
        const ColumnFixedString * c1_fixed_string = checkAndGetColumn<ColumnFixedString>(c1);
        const ColumnConst * c0_const = checkAndGetColumnConstStringOrFixedString(c0);
        const ColumnConst * c1_const = checkAndGetColumnConstStringOrFixedString(c1);
        if (!((c0_string || c0_fixed_string || c0_const) && (c1_string || c1_fixed_string || c1_const)))
            return nullptr;
        const ColumnString::Chars * c0_const_chars = nullptr;
        const ColumnString::Chars * c1_const_chars = nullptr;
        ColumnString::Offset c0_const_size = 0;
        ColumnString::Offset c1_const_size = 0;
        if (c0_const)
        {
            const ColumnString * c0_const_string = checkAndGetColumn<ColumnString>(&c0_const->getDataColumn());
            const ColumnFixedString * c0_const_fixed_string = checkAndGetColumn<ColumnFixedString>(&c0_const->getDataColumn());
            if (c0_const_string)
            {