Change the input parameter generic of FilterChain#addFilters

[Hccake]

List<GenericFilter> list = new ArrayList<>();
list.add(...);
// A cast is required here
new FilterChain().addFilters((List) list);

Using generic caps is a good way to handle this situation

[kokorin]

Despite GenericFilter is the only Filter implementation in Jaffree, list of filters should have type List<Filter>.
But there is rational basis in this PR. Could you add to this PR similar changes for FilterGraph?

[Hccake]

Despite GenericFilter is the only Filter implementation in Jaffree, list of filters should have type List<Filter>. But there is rational basis in this PR. Could you add to this PR similar changes for FilterGraph?

Ok, committed