Visual redesign of "Add Node"

[jennydaman]

Running plugins and pipelines is the quintessential feature of ChRIS, yet currently (according to user reports) it is not obvious how to do this in ChRIS_ui. Currently, the user must right-click a selected "node" to show a context menu from where "Add a node" or "Add a pipeline" can be selected.

Below is a mock-up of what a visual redesign might look like, replacing text boxes with interactive visual widgets. Here, a grey-ed out child node appears below the selected node when the mouse is nearby (i.e. inside the graph view quadrant). The proposed design is more discoverable at-a-glance.