Migrate SearchBar and SegmentedControl docs

[NathanJolly]

Background

Closes https://github.com/Shopify/pos-next-react-native/issues/36286

Solution

Migrate the docs!

🎩

Old

https://shopify.dev/docs/api/pos-extensions/ui-extensions-reference/components/search-bar https://shopify.dev/docs/api/pos-extensions/ui-extensions-reference/components/segmented-control

New

https://shopify-dev.ui-extensions-70k7.nathan-oliveira.us.spin.dev/docs/api/pos-ui-extensions/unstable/components/searchbar https://shopify-dev.ui-extensions-70k7.nathan-oliveira.us.spin.dev/docs/api/pos-ui-extensions/unstable/components/segmentedcontrol

Checklist

• [X] I have :tophat:'d these changes
• [X] I have updated relevant documentation

[github-actions[bot]]

We detected some changes in packages/*/package.json or packages/*/src, and there are no updates in the .changeset directory. If the changes are user-facing and should cause a version bump, run yarn changeset to track your changes and include them in the next release CHANGELOG. If you are making simple updates to repo configuration, examples, or documentation, you do not need to add a changeset.