#547: Add tests for new PrescribedPermutation algorithm

[cwschilly]

Fixes #547

Cases tested in this PR:

• load-only: W_max=2.0
• off-node-communication-only: W_max=0.0

---

This PR makes the same changes as #541 to write out w_max.txt when we run LBAF.

I also altered the LBAFApplication.run() function so that we can call it directly from tests with a configuration dict. This allows us to:

1. avoid using subprocess.run() to call LBAF
2. avoid having to create separate configuration files for each test case

Now we can run LBAF in tests with:

        # Run LBAF
        lbaf = LBAFApplication()
        lbaf.run(cfg=config, cfg_dir=acceptance_dir)