Summary:
Several things:
* The mess with insets was fixed. Previously we tried to compensate the insets difference with `UITextField` by adjusting `textContainerInset` property, moreover we delegated negative part of this compensation to the view inset. That was terrible because it breaks `contentSize` computation, complicates whole insets consept, complicates everything; it just was not right. Now we are fixing the top and left inset differences in different places. We disable left and right 5pt margin by setting `_textView.textContainer.lineFragmentPadding = 0` and we introduce top 5px inset as a DEFAULT value for top inset for common multiline <TextInput> (this value can be easilly overwritten in Javascript).
* Internal layout and contentSize computations were unified and simplified.
* Now we report `intrinsicContentSize` value to Yoga, one step before auto-expandable TextInput.
Depends on D4640207.
Reviewed By: mmmulani
Differential Revision: D4645921
fbshipit-source-id: da5988ebac50be967caecd71e780c014f6eb257a
1b013cd30c