The patch introduces a new command .uno:ImportMathClipboard to module Math.
It imports MathML content from clipboard and transforms it to Starmath
It handles clipboard MIME type 'application/mathml+xml' and
plain text, which can be interpreted as MathML segment.
It partly solves issues #i14252, #i34781, and #i53509 too.
Review by: Hanya <hanya.runo@gmail.com>