[oar-properties] add the gpu and gpudevice OAR properties.

Needed as soon as the gpu and gpudevice properties are created in all the OAR database, so that

• the jenkins script does not fail, like https://intranet.grid5000.fr/jenkins/job/test_oarproperties/site_cluster=lille-chetemi/2389/console
• the OAR properties wiki page knows about gpu.

merged

mentioned in commit 7490677e