Implement support for a prefix in the blood referral forms

[Nicklas Nordborg]

In a near future, blood referral form will have a prefix added to their barcodes (see #1309) due to demands from BD47 that referral form ID values must be unique.

The blood registration wizard should more or less simply ignore the prefix. But we would also like to store the full ID in a new annotation, for example: BD47_ID. This is similar to the handling of follow-up blood where the ID from the referral form is stored in BloodRccidNumber.