Remove abort in props parsing

Summary:
Goals are:

1. Catch errors in parsing during dev-mode in a way that is disruptive/grabs attention, but has enough information.
2. Use react_native_assert for hitting breakpoints (less useful for Android, more for iOS), and add LOGs for when this code is used in Android (more useful for Android, less useful for iOS).
3. Return sane defaults so that prod cases don't crash, and don't return totally garbage data.

I also found a couple cases where parsing was incorrect before; see WritingDirection and TextAlignment. This could impact some layouts and RTL/LTR potentially.

Changelog: [Internal]

Reviewed By: fkgozali

Differential Revision: D27540903

fbshipit-source-id: 99e6949d97e8ef5520d008c1df3cbe408b5a43a4