updated tests with helper classes

[nphias]

fixes bug : https://github.com/evomimic/map-holons/issues/100

[evomimic]

• The get_all_holons dance retrieves all holons from the persistent store (i.e., DHT) NOT the staging area.
• I'm proposing we stick with the terminology _stage_newholon in preference to create or add to reinforce the distinction between staging holons and committing them to the persistent store.

I added a commit that updated the test case console messages to more accurately reflect the above.

[evomimic]

What this enhancement brought into focus is the need for a deeper discussion and definition of the MAP's client-side architecture. Essentially, we need to implement the model layer of the client-side MVC architecture for the MAP's Uniform API. Since the Uniform API is THE interface for invoking everything in the MAP, it is worth devoting some extra attention to it.

I believe this model layer will look significantly different than the _tests/src/mapholons/holons/common.ts definitions included in this PR. But rather than hold up this PR, I'm going to proceed with the merge and document my thoughts elsewhere regarding design of the model layer classes and functions.