[10.x] Fix date validation issues

[mateusjunges]

Fixes #49955
Fixes #49988

This is an alternative to #49956

In Laravel v10.42.0, we can validate that a date is after or before another one, adding/subtracting a given amount of minutes, hours, seconds:

$data = [
    'dt1' => '2020-01-01',
    'dt2' => '2024-01-01',
];

Validator::make($data, [
    'dt1' => 'required|date',
    'dt2' => 'required|date|after:dt1 +1 day', //dt +1day also works
]);

PR #49871 broke this behavior and the nested after date validation.

I tried to fix both issues without reverting the original PR. Also added tests to make sure after and before are working as expected now.

[mateusjunges]

Just explaining why count() > 1 is enough here. We have the following options:

User validates using after:date_field

This is the most straight forward case. The $dateAttributes array contains only one item and we don't execute the if block.

["date_field"] // count = 1

User validates after:date_field +1day

Now, $dateAttributes contains this array:

["date_field", "+1day"] // count = 2

User validates with after:date_field +1 day

In this scenario, $dateAttributes will be

["date_field", "+1", "day"] // count = 3

User validates with after:date_field + 1 day

Here, $dateAttributes contains

["date_field", "+", "1", "day"] // count = 4

[taylorotwell]

Reverted original PR. Will release that before trying again.

[mateusjunges]

@taylorotwell should I send this again once you release the new version?