Add warning when user is about to lose data about distance-direction-addin-dotnet

[topowright-zz]

@lfunkhouser @mcalamito Do we still need this feature with the current changes that we have made with others features.

[mcalamito]

@topowright @lfunkhouser I think we are OK for now. I personally do not want to close this issue or remove it until I hear direct feedback from the customer. I think we currently have implemented a defense mechanism for the most part, but need more direct feedback.

[topowright-zz]

This will not be addressed in the first release and we need to discuss further if this is really needed. @mcalamito

[mfunk]

Tried this on build 1057 and switching tabs with values still in parameter boxes will clear them out and loose data. However I feel this is a minor issue. At best the boxes would retain the values between tab switching, but then what happens if they want to change all of the values? Adding a "Clear Dialog" button would be too much. I'm in favor of keeping it as-is.

[topowright-zz]

This is no longer an issue. Feature persist after they have been drawn on the map when switching between tabs.