Adding filter options to backup list

This patch adds filter options to backup list.
Like cinder list, now cinder backup-list accept
parameters.
This blueprint is complimented with the client part

https://blueprints.launchpad.net/python-cinderclient
/+spec/add-filter-options-to-backup-list

blueprint: add-filter-options-to-backup-list

DocImpact
Change-Id: I9e095ee44a03744eb3f319323d9130a89196614e
Merge "Adding filter options to backup list"