computeConnectionPoint doesn't respect links_render_mode

[chrisgoringe]

At litegraph.js:9767 it says computeConnectionPoint returns the link center point:

   //returns the link center point based on curvature
    LGraphCanvas.prototype.computeConnectionPoint = function(

But in fact the function takes a value t to specify distance along the link. It then assumes a LiteGraph.SPLINE_LINK in calculating the path. This is correct for all paths if t=0.5 (the original usage, I assume, from the comment) but incorrect for other values of links_render_mode.

As a result any use of the flow animation is broken for links_render_mode != LiteGraph.SPLINE_LINK