Add ability to split network at specific linear event locations.

[dblodgett-usgs]

Will require passing in a set of linear events to: https://dblodgett-usgs.github.io/hyRefactor/dev/reference/split_flowlines.html Should also implement a new input to: https://dblodgett-usgs.github.io/hyRefactor/dev/reference/split_flowlines.html to pass in the list.