Support edits in the XmlPanel code editor

[a-asaad]

Currently, the Canvas UI allows users to edit diagrams, which then generate the corresponding integration XML. However, the inverse transformation (editing the XML to update the diagram) is not supported. Adding this capability would improve flexibility by allowing users more control when creating flows.

XML to diagram conversion is handled by the flow-translator's translation/toFlow endpoint. This endpoint is already used by the XML file drop feature, see canvasDropHook.ts for the implementation details. The existing logic should be reusable when implementing the XmlPanel editing feature