Include more errors in offline data usage processing email

Problem

As a follow-up to #5551 (closed) and motivated by this comment, we can further improve the transparency of offline data usage report processing errors by including other possible errors in the email.

Proposal

On top of what was done in #5551 (closed), include the errors suggested by the review feedback above.

Result

More errors are detailed in the email going to customers.

Next steps (if any)

How will we measure success?