Before migrating to new JSON based test list, there's some intermediate steps we may do, for example:

- Current test list is usually based on 'TestListArg', which combines both test helper functions and options.
  We should isolate that into several sub components, just like JSON test list was designed - having a TestListArg that contains only constants (or simple properties), then a test list helper to create test items with simple function calls.

- Also, we should eliminate dynamic test list data by execution of commands (either using Device API or simple local execution). In otherwords, we should prevent deciding thermal sensors by dut.thermal.* calls. Also not deciding test list params by sys_utils.InChroot.

As an example, we can start migrating Reef ToT or Eve ToT.