~jaro/balkon

ref: 58f69b24f9a2138833dd86fbc8a1590760fecf64 balkon/test/Data/Text/ParagraphLayout/Internal d---------
Allow empty lines when hard line breaking.
Reduce test dependencies on fonts.
Properly use ICU locale identifiers.
Refactor line breaking.
Allow breaking at character bounds.
Implement trimming spaces at end of lines.
Move non-public modules into Internal namespace.