Add named runs and get_env_config()

[apaz-cli]

Let's slowly unify the way we handle configs and env vars. We can slowly move over to using the new get_env_config().

# Then returns ZERO_BAND_TRAIN_MEMORY_PROFILER_FREQ if set in env.
# Then returns 10 if train or config.train.memory_profiler are None.
# Otherwise, returns the value of config.train.memory_profiler.freq.
get_env_config(config, "train.memory_profiler.freq", 10)

Hopefully being able to use an env var for named runs will prevent losing experiment results in the future. And having all the configs in one place demystifies some things.

[samsja]

lfgtm !