Add DataAnnots before splitting into Tables

[heijul]

The "MRB RE3 RB30" (local) file can not be read properly, because the table is split at the (undetected) DataAnnots.

So either we need to

• find a better way of detecting which fields actually split a Table,
• try to infer the FieldType of contained Cells and add DataAnnot Cells beforehand,
• or, merge Tables with missing StopColumn/Row