Updated RNCClipboard to 1.5.1 and patched to add image support

Summary: Added setImageFromBase64(String), getPNGImageData(), getJPGImageData(), getImageData(), and getImageFilePath() to RNCClipboard. The first three allow for general purpose copying/pasting of images to the iOS Pasteboard. The latter two require additional processing on the JS side and are targeted for the Squadcal image pasting use case.

Test Plan: The first three functions have been tested in a seperate React Native testbed application. The latter two will be tested following the image paste emitter and image paste subscriber diffs. It will be important to try out all of the image types that iOS supports (ie RAW/HEIC).

Reviewers: ashoat, palys-swm

Reviewed By: ashoat

Subscribers: KatPo, zrebcu411, Adrian, atul

Differential Revision: https://phabricator.ashoat.com/D576