Option to remove basics from card pool

[NerdyNathan]

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[NerdyNathan]

Pull request for #430

[Senryoku]

Looks good, thank you very much!
Now that I see it, I realize that this doesn't make much sense for GridDraft since we generate packs of an expected known size there.
I think I'll also factor the removeBasics call out of generateBoosters, this function is already pretty complicated and removeBasics should be called in all branches, I think it make sense to have the start* functions handle that directly.
I'll add these changes to this branch, hope that's ok!

[NerdyNathan]

Yup, sounds good, I think that was my initial idea to call it in each start* method, but figured we could just call it upfront when generating the boosters. 😁
Re: the complexity of generateBoosters, I saw a couple places to clean it up that will hopefully improve readability. I'll open another pull request and you can see if you agree!