Improvement/cxp 2924 single select title prop

[n8thegr8]

PR Checklist

Description of changes: Add an optional title to the single select

Invisible selected change:

Link(s) to Storybook on docspot: https://docspot.adnxs.net/projects/lucid/improvement_CXP-2924-SingleSelect-Title-Prop/?path=/docs/controls-singleselect--basic

https://jira.xandr-services.com/browse/CXP-2924 https://jira.xandr-services.com/browse/CXP-2955

• Manually tested across supported browsers

  • [x] Chrome
  • [ ] Firefox
  • [ ] Safari

• [x] Two core team engineer approvals

• [x] One core team UX approval (as necessary)

• [x] Unit tests written (common at minimum)

• [x] PR has one of the semver- labels

https://docspot.adnxs.net/projects/lucid/improvement_CXP-2924-SingleSelect-Title-Prop

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