Bug 22071: Make authenticate_api_request stash koha.user in OAuth use case

Bug 22071: Make authenticate_api_request stash koha.user in OAuth use case

This patch makes the OAuth code stash the requestion Koha::Patron.

To test:
- Apply the tests patch:
- Run:
  $ kshell
 k$ prove t/db_dependent/api/v1/auth_authenticate_api_request.t
=> FAIL: Tests fail :-(
- Apply this patch
- Run:
 k$ prove t/db_dependent/api/v1/auth_authenticate_api_request.t
=> SUCCESS: Tests pass :-D
- Sign off =D

Signed-off-by: Charles Farmer <charles.farmer@inLibro.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 613a0034e08af84af1e2198156bbfc6900ba6551)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>