Change path prefix / unique_id behaviour

[Jammy2211]

Currently, the following code is meant to change the output paths based on both the path_prefix and unique_id variables:

search = af.DynestyStatic(
    path_prefix=path.join("build", "model_fit"),
    unique_tag=dataset_name,
    nlive=50,
    number_of_cores=2,
)

The code above would put the inner folder as dataset_name, which would be contained in a folder output/build/model_fit.

There are bugs / weird issues occurring for this, and it is also not explicit what the behaviour is.

I think we should change the behaviour such that the unique_tag is not used in order to create the paths. It is only used to change the unique identifier.

Therefore, if we wanted the dataset_name to be the outer folder, reproducing the output above, we would input:

search = af.DynestyStatic(
    path_prefix=path.join("build", "model_fit", dataset_name),
    unique_tag=dataset_name,
    nlive=50,
    number_of_cores=2,
)