CI Jenkinsfile: modular setup of script_env to support multiple uses
CI Jenkinsfile: modular setup of script_env to support multiple uses

Instead of defining script_env fully before starting docker session,
we make majority of settings global and move to start of file.
Locally used part is separated, set dynamically before calling docker.
This enables future use of global env for multiple calls of docker.

Signed-off-by: Olev Kartau <daa0e368367f231b2eec38ece459024257643988@intel.com>

mythi/intel-iot-refkit,intel/intel-iot-refkit,jairglez/intel-iot-refkit,intel/intel-iot-refkit,mythi/intel-iot-refkit,klihub/intel-iot-refkit,YinThong/intel-iot-refkit,YinThong/intel-iot-refkit,klihub/intel-iot-refkit,ipuustin/intel-iot-refkit,YinThong/intel-iot-refkit,intel/intel-iot-refkit,klihub/intel-iot-refkit,intel/intel-iot-refkit,jairglez/intel-iot-refkit,YinThong/intel-iot-refkit,mythi/intel-iot-refkit,intel/intel-iot-refkit,ipuustin/intel-iot-refkit,mythi/intel-iot-refkit,intel/intel-iot-refkit,YinThong/intel-iot-refkit,jairglez/intel-iot-refkit,jairglez/intel-iot-refkit,ipuustin/intel-iot-refkit,ipuustin/intel-iot-refkit,klihub/intel-iot-refkit,intel/intel-iot-refkit,ipuustin/intel-iot-refkit,jairglez/intel-iot-refkit,ipuustin/intel-iot-refkit,jairglez/intel-iot-refkit,jairglez/intel-iot-refkit,ipuustin/intel-iot-refkit,YinThong/intel-iot-refkit,klihub/intel-iot-refkit,mythi/intel-iot-refkit,YinThong/intel-iot-refkit,klihub/intel-iot-refkit,mythi/intel-iot-refkit,klihub/intel-iot-refkit,mythi/intel-iot-refkit