addEdge passes targetID as both source and target to edge validation

[avinxshKD]

In 3-component.js, the addEdge method calls this.validiateEdge() with edgeData.targetID for both the sourceID and targetID parameters:

const message = this.validiateEdge(edgeLabel, edgeStyle,
    edgeData.targetID, edgeData.targetID, null, 'New');

The third argument should be edgeData.sourceID.

Steps to reproduce

1. Define a custom edge validator that relies on the source node's label (e.g., reject edges originating from a specific node)
2. Try to create an edge from that node to another node via the edge creation modal
3. Observe that the validator sees the target node's label for both source and target, so it doesn't reject the edge

Expected behavior:
validiateEdge receives the actual source node ID so validators can correctly distinguish source from target

Actual behavior:
The target node's ID is passed as both sourceID and targetID, making source-aware validation logic ineffectiv

[avinxshKD]

@pradeeban What do you say? can work on this fix?

[pradeeban]

Sure, go ahead!