fix : article pages, refactor and better test data generation

crawlers:

• Remove constructor when it is not necessary
• Move get_or_create_source and get_or_create_periode into static methods
• Use article.fpage and article.lpage when possible instead of article.page_range

cleanup_str:

• Normalize strings using NFKC (Unicode)
• Remove some characters (\xf7, \r) in strings

tests:

• Update test data
• Sort test data jsons by key
• Allow regenerating the same dataset: use --keep