Filter on observation summary vectors in `ParameterAnalysis`

[lindjoha]

I have a suggestion for the plot to the bottom right of the second tab in ParameterAnalysis where the plugin is showing the summary vectors that are correlating with the selected parameter. Here it would be nice to be able to filter on the summary vectors that are used as observations in the assisted history match. Otherwise there is very often a lot of irrelevant summary vectors in this list.