(Optional) Specifiy to context to load the canvas.
targetElement - [type: HTMLElement] - The element to create a new canvas into.
subCanvasViewContainer - [type: dundas.view.controls.SubCanvasViewContainer] - The sub canvas view container to load the new canvas into.
loadingCallback - [type: Function] - If a sub canvas is being loaded, a callback can be provided to be called before the dashboard is loaded, but after onLoaded actions. The argument is the dashboard adapter.