New Component: React Accordion

[joesnellpdx]

Ensure all other accordion component issues have been addressed.

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Coordinate with the accordion block in the block library to ensure both work in tandem: https://github.com/10up/block-library/tree/trunk/includes/blocks/block-editor/blocks

[rdimascio]

Just noting there was previously ongoing work on this component here: https://gitlab.10up.com/react-components/react-accordion

cc @dainemawer

[joesnellpdx]

@dainemawer was that project intended to be part of Baseline or something stand alone? If part of baseline and still viable, we should pull it into this repo @rdimascio @dainemawer ...

UNLESS... I'm missing something ... which is very possible... let me know if that is the case.