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