Fix weekNumbers update

[stsrki]

Blazorise PR Megabit/Blazorise#6071

We need to fix update of weekNumbers property so that it can be toggled dynamically

https://github.com/Megabit/Blazorise/blob/master/Source/Blazorise/wwwroot/datePicker.js#L340

Example

<Field>
    <Button Color="Color.Primary" Clicked="@(() => showWeekNumbers = !showWeekNumbers)">
        Toggle Week Numbers
    </Button>
</Field>

<Field>
    <DatePicker TValue="DateTime?" ShowWeekNumbers="@showWeekNumbers" />
</Field>
@code {
    bool showWeekNumbers = true;
}