[Scrubber] - Push statistics of scrub jobs

[JeffreyDevloo]

[wimpers]

after discussion with @jtorreke , can we add:

• status of the job (ok, failed)
• batch size - as in the number of disks requested to be scrubbed (if available)

[jtorreke]

• batch size
• number of successfully scrubbed vdisks
• number of failed vdisks

[sjovdnbos]

Fixed by:
#2115: openvstorage-2.13.0-dev.1531317306.2b53593
openvstorage/framework-extensions#137: openvstorage-extensions-0.4.2-dev.1531311919.0eeb480
openvstorage/framework-alba-plugin#601 :openvstorage-sdm_1.13.0-dev.1531316493.7a07f16

[JeffreyDevloo]

Released in https://github.com/openvstorage/framework/releases/tag/2.13.0