TEXT-231: WordUtils.wrap react to pre-existing "newline string"

[michaelkarnerfors]

WordUtils.wrap made to react to pre-existing "newline string" as a wrap

• The main loop is completely rewritten, aiming to increase legibility of the code
• The wrap method now respects pre-existing newline strings
• An inconsistency in how zero-length "wrapOn" patterns are treated has been addressed
• Test cases for the wrap method are made parametrised and named
• Minor Javadoc fixes