Ranking/sorting of parameters based on correlation

[jorgenherje]

Ranking/soring of the parameters based on how "important" or correlated they are.
It can also be used as filtering by removing parameters with little correlation.
This can also be visualized as done in the existing ParameterAnalysis plugin in webviz-subsurface.

From discussion in: #321:

• Provide functionality for parameter filtering #321 (comment)
• Provide functionality for parameter filtering #321 (comment)