Do not drop "Given anonymously" indicator when constituent is changed in an BBIS batch
When a constituent is manually selected in a BBIS batch, the "given anonymously" indicator is removed from the gift. Since this anonymous indicator is at the gift level (not constituent level), the anonymous indicator should remain after the constituent is changed. "Given anonymously" is very different from the "Gives anonymously" indicator which is at the constituent level. We need any gift "given anonymously" in BBIS to remain that way throughout the batch processing.