Changes to Get Project Summary

added the new optional query request parameter period

added the optional property kpis/items/change_pct to the response with the 200 status

added the optional property kpis/items/previous_sample_size to the response with the 200 status

added the optional property kpis/items/previous_value to the response with the 200 status

added the required property period to the response with the 200 status

endpoint added