Description
With #11673 we got support for dates in validators but we do not have any option to change the formatting of the compared_value for message when the input date is invalid and we get a validation message.

Example

Current

/**
 * @Assert\GreaterThanOrEqual("2020-01-01")
 */
private $date;

Now with an invalid field we would get a validation message like:
This value should be greater than {{ compared_value }}.
real output:
This value should be greater than Jan 1, 2020, 12:00 AM
Now i see a full date with hours and minutes that i didn't pass as value.

Proposal

/**
 * @Assert\GreaterThanOrEqual(value="2020-01-01", messageFormat="Y-m-d")
 */
private $date;

Now with an invalid field we would get a validation message with our date format like:
This value should be greater than 2020-01-01.

What we also could do is look at what the input was for example value="2020-01-01 08:00" we get something like:
This value should be greater than 2020-01-01 08:00 AM because we specified hours but this might cause backwards compatibility errors as default behavior will change.

This will apply to all comparisons where we can validate date input see #11673. Let me know what you guys think i can work on a pull request if it sounds good.