Select plugin+configuration in a single list
The current dialog for selecting a plug-in + a configuration has two lists. One list for selecting the plug-in and then a second list for selecting a configuration. The second list is updated automatically based on the selection in the first list.
The problem is that it is sometimes difficult to find the correct plug-in. In particular in the analysis part were a lot of plug-ins are listed as configurations for the Base1PluginExecutor.
It may be better to merge the two lists into a single list with an "internal" two-level structure. Eg. plug-ins are listed in the top-level and configurations are listed below but with a slight indentation.
Need to verify that this works properly for all plug-ins depending on if they need and have a configuration or not.