refactor: support multipass executions

Intent of Change

Refactor (non-breaking change which improves the structure or operation of the implementation)

updates createTemplate to provide a generation contract stage to the engine during template generation
updates the script to then handle multiple output validation for each process_template_pass invocation
fixes https://github.com/hamlet-io/executor-bash/issues/185

Generating multiple outputs at a time reduces duplication of the setup processes required in the engine. Part of https://github.com/hamlet-io/engine/issues/1666

Initial testing shows some improvements in performance

time hamlet -i mock -p aws -p awstest deploy test-deployments

multipass

real    9m38.630s
user    11m33.315s
sys     2m16.764s

single pass

real    13m2.916s
user    15m29.790s
sys     3m6.966s

Further improvements will be added in the future to generation outputs during the initial generation contract generation.

Tested locally