Support panel height

[manueligno78]

Seems that gripPos object is not managed by the tool. Should be cool to support this object to have some additional functionalities like panel height setting.

{ "content": "<a href=\"link">Latest release notes</a>\n", "description": null, "mode": "html", "title": "", "type": "text", "gridPos": { "x": 0, "y": 1, "w": 24, "h": 14 }, "id": 2 }