~jaro/balkon

ref: 4ff2ea2a04080eb644de0fba63237633c025ab0d 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.