Enhancing Flexibility in Priorband Usage: Allowing Partial Knowledge Without Mandatory Default Parameters

[danrgll]

It would be beneficial to have the ability to add partial knowledge to the configuration area, especially for using Priorband, without having to set the "default" argument for all the parameters.

Example:

pipeline_space = dict(
    hyperparameter_a=neps.FloatParameter(lower=1e-5, upper=1e-1, log=True),
    hyperparameter_b=neps.IntegerParameter(lower=1, upper=20, is_fidelity=True), 
    hyperparameter_c=neps.IntegerParameter(lower=32, upper=128, **default=64, default_confidence="medium"**), # my knowledge 
)