Support not needing to pass in a noop function to call functions in the opt chain

[lucasdellabella]

Feature request:

Currently to invoke a function in the chain I need to do something like this

const a: any[] | null = ...
oc(a).push(() => {})('my value')

So I don't have to pass noop functions in that make my code nasty could we do something like
oc(a).push._('my value')
that would invoke the function if it exists, if the chain is undefined it just returns undefined? I don't mind submitting a PR