Parsing of file addition metadata

Dependencies

• [2] VO5OQW4W Removing anyhow in libpijul
• [3] 73NW2X2M Returning a parse error instead of panicking when parsing a text change
• [4] KJDQ2WOM Fixing the parsing of section headers in the text change format

Change contents

• replacement in libpijul/src/change/text_changes.rs at line 565
  [2.59326]→[2.59326:59365](∅→∅)
  − parent.to_string()
  [2.59326]

  [2.59365]
  + parent.to_string() + "/"