DraCor platform updates

Several major DraCor platform components have been released with new versions in July:

• the DraCor API 1.4.0 now supports editor elements in the titleStmt and idno elements to encode Wikidata IDs for characters, allows to fine-tune segmentation with the refsDecl/citeStructure declaration and adds a new (experimental) /characters endpoint.
• the DraCor Frontend 2.7.0 can display translators alongside authors
• the DraCor Schema 1.5.0 improves assistance with encoding Wikidata IDs and adds guidance for new API features
• the DraCor Validate Action 2.5.0 and the DraCor Oxygen Framework 1.1.0 have been updated to support the latest DraCor Schema.