Prevent NY filers from claiming both college tuition credit and deduction

[MaxGhenis]

From https://www.nysenate.gov/legislation/laws/TAX/615 (d)(4) on the college tuition itemized deduction:

Provided, however, no deduction shall be allowed under this paragraph to a taxpayer who claims the credit provided under subsection (t) of section six hundred six of this article.

And https://www.nysenate.gov/legislation/laws/TAX/606 (t)(4) on the credit:

(6) Limitation. No credit shall be allowed under this subsection to a taxpayer who claims the itemized deduction provided under paragraph four of subdivision (d) of section six hundred fifteen of this article.

We currently approximate this by only allowing the credit for non-itemizers. Proper modeling will require branching so low priority given the computational complexity.