Module structured 

Structured field parsers: converts typed sub-fields into model types.

All parsers follow the same convention:

• Accept &[Line], &mut usize (pos), &mut Vec<AgmError>
• On entry, *pos points to the first line AFTER the FieldStart line
• Field content ends when a line’s indent < base_indent (non-blank), or a NodeDeclaration is encountered, or EOF