Node handles are always on right or left

[gcoutable]

No description provided.

[gcoutable]

Initially handles were initialized on the left and the right of nodes every time a refresh event payload was received, which was happening rarely.
Since #2262 we share the position and size of nodes between all opened diagram instances which implies a diagram refresh payload for all opened diagrams on every change, and thus, always initializes node handle position to the left and right of nodes

[gcoutable]

The first thing to do will be to execute the algorithm that sets the position of handles on the conversion.