The string '< Hidden >' was agreed on as a good default, so we will use the hidden_field key.
I also moved the definition in en.yml up to the more general area at the start of admin.reports section (before it was hidden between report-specific keys.
when permitted.
The MaskDataService is used by the report framework, so this should affect all reports. It would be nice to test all reports, but I figured it wasn't worth it (already we only test one report for masking names).
We now update or create line item fees instead of deleting them and
recreating them. This is to cover the case when a product has been
removed from an Order Cycle but we want to keep the fee already applied
on existing order. This was an issue only if the existing order got
updated after the product was removed.
