~jaro/balkon

ref: dbcfcd67306ba9ba4b66b55f70fa6d0f869e90c4 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.