Improve the conversion workflow

[pasqLisena]

What the converter does now:

• for each Class (Work, Expression, Performance,...)
  • for each Property (has_title, has_genre,...)
  • parse the MARC
  • until the MARC code for that property is found
    • read the next line
  • compute and save the information

Consequently, the MARC file is parsed at each step.

A better workflow could be:

• parse the MARC
• for each Class (Work, Expression, Performance,...)
  • for each Property (has_title, has_genre,...)
  • search the MARC code for that property
  • compute and save the information

That search will remain a full search, but the XmlReader will expose a proper method (from code to line).