Merged PR 235: Refactor describe_state to use name/hostname instead of UUID as primary key

## Summary
- Refactor Simulator state to use service/application name instead of UUID, and node hostname instead of UUID.
- Refactor observations to read the hostname/name instead of UUID.
- Refactor rewards as well.
- Refactor configs to specify name instead of reference that will be translated to UUID.

## Test process
Existing unit tests pass. Inspected the printout from running 'describe_state' on arcd_uc2_network' to verify that names are used to report state.

## Checklist
- [x] PR is linked to a **work item**
- [x] **acceptance criteria** of linked ticket are met
- [x] performed **self-review** of the code
- [na] written **tests** for any new functionality added with this PR
- [na] updated the **documentation** if this PR changes or adds functionality
- [x] written/updated **design docs** if this PR implements new functionality
- [na] updated the **change log**
- [x] ran **pre-commit** checks for code style
- [x] attended to any **TO-DOs** left in the code

Related work items: #2131

tests/integration_tests/game_layer/test_observations.py

@@ -14,7 +14,7 @@ def test_file_observation():
     state = sim.describe_state()
 
     dog_file_obs = FileObservation(
-        where=["network", "nodes", pc.uuid, "file_system", "folders", "root", "files", "dog.png"]
+        where=["network", "nodes", pc.hostname, "file_system", "folders", "root", "files", "dog.png"]
     )
     assert dog_file_obs.observe(state) == {"health_status": 1}
     assert dog_file_obs.space == spaces.Dict({"health_status": spaces.Discrete(6)})