feat(cxl-lumo-styles): add spinner to checkout submit button

[anoblet]

https://app.clickup.com/t/86b040y1c

[github-actions[bot]]

size-limit report 📦

Path	Size
packages/cxl-ui/pkg/dist-web/cxl-ui.js	74.4 KB (+0.05% 🔺)
packages/cxl-ui/pkg/dist-web/cxl-ui-jwplayer.js	11.89 KB (0%)
packages/cxl-ui/pkg/dist-web/cxl-ui-playbooks.js	30.98 KB (+0.1% 🔺)
packages/cxl-ui/pkg/dist-web/vendor.js	140.5 KB (0%)
packages/cxl-ui/pkg/dist-web/cxl-ui-jwplayer.js, packages/cxl-ui/pkg/dist-web/cxl-ui-playbooks.js, packages/cxl-ui/pkg/dist-web/cxl-ui.js, packages/cxl-ui/pkg/dist-web/manifest.js, packages/cxl-ui/pkg/dist-web/unresolved.js, packages/cxl-ui/pkg/dist-web/vendor.js	258.92 KB (+0.03% 🔺)

[pawelkmpt]

Screenshots before/after would be useful

[pawelkmpt]

I think it's this piece