Bug 34271: Remove a few Logger statements from REST API

Bug 34271: Remove a few Logger statements from REST API

See also bug 22678.
We should call app->log->warn, ->debug, etc. instead of Logger.

Test plan:
The simplest way I tested V1, is add a app->log->warn in the try
blocks, restart all and check that your log4perl is set correctly
too.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: David Cook <dcook@prosentient.com.au>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit a3ce05012b8a2ee6b47c82d14f61c082798ab8a1)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>