Added new message (KpiDescriptorFilter) and updated method name

import "kpi_sample_types.proto";

service KpiManagerService{

  rpc SetKpi                (KpiDescriptor      ) returns (KpiId               ) {} // Stable not final

  rpc DeleteKpi             (KpiId              ) returns (context.Empty       ) {} // Stable and final

  rpc SetKpiDescriptor    (KpiDescriptor      ) returns (KpiId               ) {} // Stable not final

  rpc DeleteKpiDescriptor (KpiId              ) returns (context.Empty       ) {} // Stable and final

  rpc GetKpiDescriptor    (KpiId              ) returns (KpiDescriptor       ) {} // Stable and final

  rpc GetKpiDescriptorList  (context.Empty      ) returns (KpiDescriptorList   ) {} // Stable and final

  rpc SelectKpiDescriptor (KpiDescriptorFilter) returns (KpiDescriptorList   ) {} // Stable and final

}

message KpiId {

  context.Uuid kpi_id = 1;

}

message KpiDescriptor {

  KpiId                          kpi_id          = 1;

  string                         kpi_description = 2;

  repeated KpiId                 kpi_id_list     = 3;

  kpi_sample_types.KpiSampleType kpi_sample_type = 4;

  context.DeviceId               device_id       = 5;

  context.EndPointId             endpoint_id     = 6;

  context.ServiceId              service_id      = 7;

  context.SliceId                slice_id        = 8;

  context.ConnectionId           connection_id   = 9;

  context.LinkId                 link_id         = 10;

  kpi_sample_types.KpiSampleType kpi_sample_type = 3;

  context.DeviceId               device_id       = 4;

  context.EndPointId             endpoint_id     = 5;

  context.ServiceId              service_id      = 6;

  context.SliceId                slice_id        = 7;

  context.ConnectionId           connection_id   = 8;

  context.LinkId                 link_id         = 9;

}

message KpiId {

  context.Uuid kpi_id = 1;

message KpiDescriptorFilter {

  // KPI Descriptors that fulfill the filter are those that match ALL the following fields.

  // An empty list means: any value is accepted.

  // All fields empty means: list all KPI Descriptors

  repeated KpiId                          kpi_id          = 1;

  repeated kpi_sample_types.KpiSampleType kpi_sample_type = 2;

  repeated context.DeviceId               device_id       = 3;

  repeated context.EndPointId             endpoint_id     = 4;

  repeated context.ServiceId              service_id      = 5;

  repeated context.SliceId                slice_id        = 6;

  repeated context.ConnectionId           connection_id   = 7;

  repeated context.LinkId                 link_id         = 8;

}

message KpiDescriptorList {