[FEATURE] add jsr305 annotations to built classes

[xenoterracide]

Describe the feature

@Builder
class Foo {

    @NonNull
    private final String bar;
}

...
public FoleyConnectionEvent.FoleyConnectionEventBuilder gatewayId(@NonNull @Nonnull final String gatewayId) {
            if (gatewayId == null) {
                throw new NullPointerException("gatewayId is marked non-null but is null");
            } else {
                this.gatewayId = gatewayId;
                return this;
            }
        }

Describe the target audience
anyone trying to emulate kotlins null safety

Additional context
a bug within a null checker
uber/NullAway#321

might also be worth it to add some support for different annotations, like a lombok property to add annotations to the generated classes