[clang-tidy] Added DefaultOperatorNewCheck.

Summary:
Added new checker 'cert-default-operator-new' that checks for
CERT rule MEM57-CPP. Simple version.

Reviewers: aaron.ballman, alexfh, JonasToth, lebedev.ri

Reviewed By: aaron.ballman

Subscribers: hiraditya, martong, mehdi_amini, mgorny, inglorion, xazax.hun, dkrupp, steven_wu, dexonsmith, Szelethus, gamesh411, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67545