Well Event: Improve user interface

[magnesj]

The current representation of well event objects in ResInsight is based on the default display and ordering of object. Suggested improvements:

• create a separate root object named Well Modeling
• improve display of object names
• add grouping and/or sorting: by data, owner (well, group, field)
• add support for 3D visualization based on the selected time step for well event objects
• investigate how to support well name alias (separate file or part of event file)
• add support for fishbone and fracturing