impr(cockpit/tree): change the 	activty state icons
impr(cockpit/tree): change the 	activty state icons

related to CAM-1886

ingorichtsmeier/camunda-bpm-platform,langfr/camunda-bpm-platform,langfr/camunda-bpm-platform,langfr/camunda-bpm-platform,camunda/camunda-bpm-platform,langfr/camunda-bpm-platform,camunda/camunda-bpm-platform,ingorichtsmeier/camunda-bpm-platform,ingorichtsmeier/camunda-bpm-platform,camunda/camunda-bpm-platform,ingorichtsmeier/camunda-bpm-platform,langfr/camunda-bpm-platform,camunda/camunda-bpm-platform,ingorichtsmeier/camunda-bpm-platform,langfr/camunda-bpm-platform,ingorichtsmeier/camunda-bpm-platform,camunda/camunda-bpm-platform,camunda/camunda-bpm-platform