duplicatesCount does not update in OnPush change detector mode

[mareklinka]

Hello. #1015 and the related PR made several of the Toast class properties into signals, but markedly title, message, and duplicatesCount still remain simple properties. This means that in the OnPush change detection mode, updating these properties does not trigger a UI update.

This is especially problematic when duplicate prevention is enabled or when the user wants to provide their own toast component with additional logic. This limitation is not entirely blocking but I would like to ask if there is a reason that there properties remain non-reactive - and if not, whether they could be turned into signals.

ngx-toastr/src/lib/toastr/toast.component.ts

Lines 58 to 61 in e688d80

	message?: string | null;
	title?: string;
	options: IndividualConfig<ConfigPayload>;
	duplicatesCount!: number;