Make Aztec send height information to JS after pasting text

[etoledom]

Fixes #438

This is a small PR that forces layout when the user paste text. I noticed that layoutSubviews is called every time textViewDidChange is called, except for pasted text. Adding an explicit call to setNeedsLayout() solves the issue.

I tested that layoutSubviews is not called more than once for every text change, and now it's properly called after pasting text.

To test:

• Test pasting a long text in a paragraph block.
• Check that its heights grows accordingly.

[SergioEstevao]

Looking good!

[etoledom]

Thank you!