Added functionality for running CI unit tests on modified modules only

[hepromark]

Currently CI runs all unit tests on the entire mono-repo regardless of where changes actually occur. This is inefficient & wastes time, since the unit tests are specific to only 1 module and changes outside that module won't impact those tests.

• Workflow now checks which src directories (action, interfacing, etc...) are changed
• CI Will only run unit tests under those directories (if action is changed, only modules from action are unit tested)
• If no src change is detected, all tests will be ran in case of an infrastructure change which might affect everything

[hepromark]

Hi. I've added the comparison between latest commit vs. main branch for selective CI pipeline unit-testing.

• added a new job before the setup-environment job called get_changed_modules, which outputs a space delimited list of modules (ex. "action interfacing samples") whose src files were changed
• modified docker_context.sh to take an string input, the space delimited list, and only test modules which are inside that list
• if the list is empty docker_context.sh will test everything
• there are some .txt files I made to show the CI pipeline selectively testing those modules only

Let me know what needs to be changed, thanks!

[hepromark]

"add a confirm-build-and-unittest-complete job after build-and-unittest so that I can add it as a requirement to pass, instead of having all the build jobs as a requirement"

Is what I have right now satisfactory?