[NO TICKET] add learn icon

[kamiTT]

Summary

Adding a new icon that CXT uses within their application: personBook

How to test

1. Build and serve storybook.
2. Navigate to the medicare icons component
3. Confirm new icon appears: personBook

Checklist

• Prefixed the PR title with the Jira ticket number as [CMSDS-####] Title or [NO-TICKET] if this is unticketed work.
• Selected appropriate Type (only one) label for this PR, if it is a breaking change, label should only be Type: Breaking
• Selected appropriate Impacts, multiple can be selected.
• Selected appropriate release milestone

If this is a change to design:

• If visual regression image references have been changed, design MUST be assigned to review. In this instance, designer approval is a requirement before the PR can be merged.

If this is a change to code:

• Created or updated unit tests to cover any new or modified code
• Verified that running both npm run test:unit and npm run test:browser:all were each successful
• If necessary, updated unit-test snapshots (npm run test:unit:update) and browser-test snapshots (npm run test:browser:all:update)

If this is a change to documentation/content:

• Checked for spelling and grammatical errors
• Communicate the assigned milestone/release date with Design so they can communicate appropriately

[jack-ryan-nava-pbc]

not a wolf