feat: Add option to set toggleable for showConfirmDialog

[koji-1009]

I would like to suggest an option to set toggleable to false in the showConfirmationDialog method.
This is to deal with cases where user do not want to deselect an item when tapped again.

Thanks for the great library.

[mono0926]

@koji-1009

Thanks, released: https://pub.dev/packages/adaptive_dialog/changelog#1100

[koji-1009]

I appreciate your kindness.