Control panel - More error handling

[PhillipsOwen]

i am seeing this in control-panel.js, lines 107-111 (see below).

as this is an async event, this area may also need more error handling to insure that "data" exists before it is used.

also, the axios call should be using the /get_ui_data_secure endpoint.

if (isError) {
alert(error);
} else {}
// add data returned to default layers, if they are not already there.
parseAndAddLayers(data);