Changelog
- adds the ability to more easily edit large trees by enabling panning near the edge of the screen during dragging connections, which closes #246
- highlights connections attached to an Outcome when a single Outcome is selected
- fixes an issue where if the outcome creation card is opened very close to the right or bottom edge of the screen then the viewport of the screen adjusts undesirably. it should now show the card within the screen when opened and not adjust with the viewport.