Update Error Message for Quotes with Orphaned Subscription Rate Plan Ids

[Brick]

Currently if a Quote is in progress and references a Subscription Rate Plan Id, and if that Id is changed on the Zuora side, the Quote or the CPQ Apex Component will throw an error like one of the following: 

"Content cannot be displayed: common.apex.runtime.impl.ExecutionException: (convert2ZChargeGroup) Exception while converting to ChargeGroup.ystem.NullPointerException:Attempt to de-reference a null objectzqu)"

or

"(convert2ZChargeGroup) Exception while converting to ChargeGroup.ystem.NullPointerException:Attempt to de-reference a null objectzqu) Error is in expression '{!theOptions}' in component <zqu:cpqselectproduct> in component zqu:cpqselectproduct"

Since the simplest fix for this is to re-create the Quote so that it uses the latest Ids, an error message with details to that effect would be nice to have.