refs #185

refs #185

API object attribute names are now:

1. camelCased (#164)
2. use Id / Ids suffix for object references (#172)

Image uploads might take a while and even though we can’t currently show
a progress bar for the upload (because fetch upload progress is still
not a thing) we can at least indicate that something is happening and
disable any interactive UI elements.

refs #144

isProcessing seems more general purpose as it’s not clear if the
provided function actually loads something.

Using :is-open="true" interferes with the dialogs close function in
nested dialogs.

Using the same name as the native HTML dialog is a bad idea.

closes #139