Update DirectConsumer option to ignore shutdown and other reasons

[ono]

Follow up #184

[ono]

@benonymus @haljin

Tweaked the options and made consumer pid matching explicit as before. Let me know if you have any feedback.

[benonymus]

Hey @ono

Looks good to me, I like that this way the options are ready to be expanded.

I am not sure about the property named cascade, maybe something more explicit like ignore_all_reasons(would need to change it to do it if true), and then maybe change the ignore to ignore_reasons?

[ono]

Yeah, agreed. After a bit more thinking, I will go for a single option - ignore_consumer_down which takes boolean or list.

opts = [ignore_consumer_down: true] # ignore any reason
opts = [ignore_consumer_down: [:normal]] # ignore normal (default)
opts = [ignore_consumer_down: [:normal, :shutdown]] # ignore normal and shutdown