Bug 33302: (QA follow-up) Rephrase errors to be more user friendly

Bug 33302: (QA follow-up) Rephrase errors to be more user friendly

These error message will show within the patron account. The goal
of this patch is to make them a little more user friendly avoiding
'patron' and 'hold group' terminology :)

Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 4e599c790fa0a2e5909916b4f3335d2a7b2a20a9)
Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>
(cherry picked from commit ddae00994002fa79c2f766ab714cc0b0d48f450a)
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>