Import exam results, component marks and basedata

Requires permission: ExamAdmin

Accepts whatever the boards sent — JCQ a2c XML, JCQ EDI results, a Cambridge International spreadsheet, or JCQ basedata definition files — one file or several, and saves subject results, component marks and board definitions. Each file's format is detected from its contents, not its name. WorkbookMark chooses the raw, adjusted or weighted column of a spreadsheet; DuplicateHandling decides whether an outcome that already exists is added alongside or replaced; DryRun reports what would happen and writes nothing.