Preserve point IDs without a path node

[0HyperCube]

When there is no path node, the compute_modified_vector function (included below) relies on the click_targets. However click targets don't store PointIds, SegementIds, or colinear handles. This leads to a couple of issues:

• If you select a point on ellipse (no dragging) the colinear check box won't be filled.
• If the segments are in an odd order (e.g. with the bevel node), inserting a point in a segment crashes.

Graphite/editor/src/messages/portfolio/document/utility_types/network_interface.rs

Lines 2826 to 2831 in c3a3c4c

	self.document_metadata
	.click_targets
	.get(&layer)
	.map(|click| click.iter().map(ClickTarget::subpath))
	.map(|subpaths| VectorData::from_subpaths(subpaths, true))
	}

[adamgerhant]

I think it would be best to automatically insert a Path node when the editor creates vector data. I don't think relying on the click targets is a good idea.

[Keavon]

A related issue that's a consequence of this:

The Path tool's options bar checkbox for "Colinear Handles" only correctly displays the current status for a selected point if the layer has a Path node. If you draw an ellipse, none of the points have "Colinear Handles" checked until adding a downstream Path node, then the checkboxes populate their correct values. So this problem applies to vector data coming from somewhere in the graph flow without a Path node being involved, such as a vector shape generator node rather than a Path node.