B2OC: sort line dictionaries

Closes #484 (closed)

• Declare flavor_tagging_lines in spruce_b2oc.py as a list
• Sort line dictionaries when booking lines

I've tried two runs with

run gaudirun.py -n -o test[1,2].opts ./Hlt/Hlt2Conf/tests/qmtest/sprucing.qms/test_spruce_all_lines_realtime.qmt

and the outputs (test1.opts, test2.opts) are identical now.