Accessibility tweaks

- Moves prev and next buttons next to each other int he markup order so that screen readers will read them out together.
- Replaces label element for a span element because you are only supposed to have one label per input.
- Adds more text tot he label for screen readers and hides the trailing "of total". Currently this enhancement is commented out until we have access to the .u-visually-hidden utility class.
- Adds a `.pagination_content` element that can be placed on the page, the pagination will jump to it on prev/next and submit.