Summary:
The current implementation of React Native uses `Size` as the underlying type of `textShadowOffset` which is clearly terribly wrong (especially because negative size values makes no sense). This mistake was borrowed from `NSShadow`, I believe.
I don't have time to fix this in every implementation of RN now, so let's use `Size` in Fabric as well.
Reviewed By: fkgozali
Differential Revision: D8246714
fbshipit-source-id: 1f0bf9b9dfa83802ef3faef2971fed5510494bfd
8b62e7a550