Time series plotter: Allow adding groundwater nodes and lines easily

[leendertvanwolfswinkel]

In groundwater models, the surface water nodes/lines are at the same location as the groundwater nodes/lines. In the current implementation, only the first feature (i.e. the surface water feature) will be added to the plot. I changed this so that all features within a certain precision from the mouse are added to the plot.

However, if you zoom out very far and click on the map, it will freeze the Modeller Interface for quite a while and add loads of lines to your plot. I propose the following solution:

• If the number of items that are to added to the plot exceeds 10, do not add any and show the following message as a messagebar: "Please zoom in and try again. To add more than 10 items to the plot at once, use the 'Add all selected' option."

[arjanverkerk]

Without trying or testing anything, in the water balance we get a popup in which you can select from multiple geometries in multiple layers if there are more candidates within the search range. Could we use that behaviour here as well, or is it desirable to be able to select multiple features at once.