Summary Plot: Support grid cell curve type and grid cell selection in plot

[hhgs]

When "Plot time history for selected cells", make curve where case, cell indexes, property can be updated by user.
Allow grid cell curve type to be created in the Project Tree.

Next step: Link plot to grid cell selection in 3D-view.

[RezaeiDoust]

There are several other required small improvements to this plot:

1. if the parameter is changed in the "Property Editor" , "Result Property", an update in needed (can be performed by a double click) to show the new parameter.
2. if a second parameter added to a current parameter, it is not checked whether a second Y axis is needed or it can be plotted on an already Y axis.