Confusing API for checkbox without a label

[arkwright]

As per #540, an EuiCheckbox without a label prop must also receive type="inList", otherwise as of 0.0.22 it will be unclickable with a mouse. I was using a checkbox, read through the source code, was totally aware of type="inList", but didn't think to use it due to the seeming non sequitur of lists and lack-of-checkboxes.

[arkwright]

@cchaos said:

Perhaps we just need to change that prop name, or add an alias to the prop name, that says noLabel and appends that class. And we should probably add the same ability to the radio buttons as well.

I like where you're going with noLabel. Semantically and intuitively, I would ideally like to see a checkbox without a label prop simply render correctly, as I tried to do in #540. Even if it's renamed to noLabel, API consumers twice need to specify that a label is not being used: by omitting the label, and then also by adding, "no, really, this definitely does not have a label."