~jaro/balkon

ref: b7db6d117bdaa5459bd162331d9ab2d887b365f6 balkon/test/Data/Text/ParagraphLayout/Internal d---------
Remove collapsible spaces at beginning of lines.
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.