jquery.getAttrs: Replace deprecated nodeName/nodeValue with Attr.name/value

Chrome emits the following warning:
> 'Attr.nodeValue' is deprecated. Please use 'value' instead.

Attr.nodeName and nodeValue are not part of the DOM standard.
https://dom.spec.whatwg.org/#interface-attr

Attr.name and Attr.value are supported since at least IE8.
Confirmed the unit tests passing in IE8.

Simplify and improve the unit tests for jquery.getAttrs.

Change-Id: Ic086ece34b214dede26371cbc03ede0f2af37c54
Merge "jquery.getAttrs: Replace deprecated nodeName/nodeValue with Attr.name/value"