Converter for custom tag <-> XML/TEI tag conversion

[jkloe]

• Tags in Transkribus are stored in a custom tag format inside the custom attribute of a textline, word or region of the PAGE format (e.g. a textline containing the text I am a Dr. can be tagged with an abrreviation: custom="abbrev { offset:7; length:3; expansion: Doktor;}")
• To support editors that work with explicit XML/TEI like tags in the content of textlines, words or regions (I am a <abbrev expansion=Doktor>Dr.</abbrev>) a converter in both directions is needed

[jkloe]

A first draft of the converter can be found here (branch 'dev_sebi'):
eu/transkribus/core/model/beans/customtags/CustomTagConverter.java