Summary: Moved YGStyle to separate file and added default constructor to it. This diff also gets rid off of the default values, which were earlier declared in Yoga-interna.h and instead uses default constructor. This diff also addresses https://github.com/facebook/yoga/pull/700
Reviewed By: emilsjolander
Differential Revision: D7016575
fbshipit-source-id: eb28df0ffb4cc813b23edaff80d7d4ebc56ce6af