[@mantine/dates] DateInput: clear input value on clearButton click

[mrbnclt]

This fixes #4481.

When Calendar Dropdown is open then the user clicks on the clear button, the following code won't run causing the input value to not be cleared.

useDidUpdate(() => {
    value !== undefined && !dropdownOpened && setInputValue(formatValue(value));
  }, [value]);

So when user clicks on the clear button we also closes the Calendar Dropdown which fixes the issue.

As other Date components, clicking the clear button closes the Calendar Dropdown, this should also make the behavior consistent across components.

[rtivital]

Thanks!