Cover more case in roq-data type safety

[ia3andy]

Deprecate parentArray and use DataMapping.ObjectFile as default and DataMapping.ArrayFile(replacement for parentArray).

Introduce:

• DataMapping.ArrayDir: a list of data files sharing the same structure
• DataMapping.ObjectDir: the same but with the filename (without the extension) as key and data as value

[ia3andy]

@philippart-s already implemented the dirs feature without typing.