Add `overflow` and `wrap` icons to repo (for <rh-code-block>)

[coreyvickery]

SVGs attached and they look fine in Figma. Let me know if there's anything else needed.

wrap-overflow-ui-icons.zip

[bennypowers]

make sure proportions and sizes are good. i.e. these shouldn't be 24x24 if all their siblings are 16x16 or whatever. also run the optimization script / npm run build before committing