Fixes #177: handle responses of manual params in grouped_xai_expanded

[Nikronic]

Fixes #177

Summary:

• catch manual params: similar to other endpoints, it is required to catch manual params and remove them, hence preprocessing and ML models can work with the original training set.
• add pretty print of manual params response: this is particularly useful when integrated with grouped_xai_expanded endpoint, where each response of each parameter takes a XAI value and grouped together.
• add manual params responses to grouped_xai_expanded: since manual params didn't have XAI values per response in the original output of XAI, we couldn't report based on the given response the importance. Now, even these manual params are added to original XAI values, and we can report them like others. Note that these values are constant and won't change based on the change of other values.
• add ability to use a human-readable description for params: when reporting XAI values, the name of the parameter and chosen response is concatenated and reported alongside the XAI value (or importance in case of manual params). In some cases, these values are not human-readable and needs to be replaced by a descriptive one. Now, attribute description is doing that. For domain-specific manual params, these human-readable descriptions have been provided yet can be overridden on-the-fly by the user.