Modify DataArray's my_array_dtype and my_array_shape to be visible and non-editable in Wendelin's UI, in a way that does not break the tutorial notebook scripts.

This is accomplished by changing both properties' prefixes to your_ instead of my_, which causes jIO to not check the editability when fetching the corresponding array (which was the cause of the previous breakage).

Also included here is a change in the notebook tutorial script Selenium tests: the scripts now fetch the array data from the Wendelin UI hatoes endpoint instead of ERP5's, which I find is more reliable. I will update the scripts in the real tutorial pages accordingly.

These are intended as temporary fixes, until ERP5's experimental JSON APIs are stable enough to be used on Wendelin and replace the current API.