Static public methods can be called synchronously through the
API call without creating environment, object instances and
database records. It is proposed to make RPC call as the single
request-responce for now.
However async API and RPC calls may also be implemented later
exploiting the same pattern as for calling instance methods.
New call can be done through client method (see
Ib6a60f8e33c5d3593a55db9f758e94e27f0a4445)
Tempest and unit tests are added.
APIImpact
Implements: blueprint static-actions
Change-Id: I17ab2eba0fd6c42309667f42d0644d21940ab02d
7d186c191d