GUI:  support group, group_resource attributes together on group settings tab

 - Allow to set/remove group & group_resource attributes together on
   group settings tab. Also adding new attributes support new unified method.
-  Fixed confirms design when setting values to all members of group.

Before merging this commit to master, Fixes for tasks #1461 and #1462 must be merged.
GUI: fix IDS when setting new attribute fails

- In case Exception is thrown when setting new attributes,
  we must remove ids "workWithUserAttributes" and "workWithGroupAttributes"
  so inner method can properly decide namespace for another setAttributes() try.
Merge pull request #214 from zlamalp/groupResource

GUI: Group resource
Core: service identity can be group admin

There is no reason why service identities shouldn't be able to get
additional roles in core. Except that we won't be able to get real actor
form audit log for action made by the service identity. That's the risk
that user who give additional role to service identity must take.

This commit only changes behavior of add group admin. Other similar
methods are already accepting service identities.