**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

{
        if (2 != types.size())
            return false;
        auto isBigInteger = &typeIsEither<DataTypeInt64, DataTypeUInt64, DataTypeUUID>;
        auto isFloatingPoint = &typeIsEither<DataTypeFloat32, DataTypeFloat64>;
        if ((isBigInteger(*types[0]) && isFloatingPoint(*types[1]))
            || (isBigInteger(*types[1]) && isFloatingPoint(*types[0]))
            || (WhichDataType(types[0]).isDate() && WhichDataType(types[1]).isDateTime())
            || (WhichDataType(types[1]).isDate() && WhichDataType(types[0]).isDateTime()))
            return false; 
        return isCompilableType(types[0]) && isCompilableType(types[1]);
    }
    llvm::Value * compileImpl(llvm::IRBuilderBase & builder, const DataTypes & types, ValuePlaceholders values) const override