feat(segment): add keyboard navigation, add selectOnFocus property to control selection follow focus behavior

[willmartian]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue Number: resolves #23520

What is the new behavior?

• ion-segment now responds properly to keyboard navigation.

Does this introduce a breaking change?

• Yes
• No

[liamdebeasi]

This is looking great! A few small comments, but overall this is a really solid PR.

[liamdebeasi]

Functionality-wise this looks good to go. One lingering question and a couple docs changes.

[liamdebeasi]

Great job! Once the builds pass this is good to merge. Be sure to mark this as a feature since we are adding an API.

I updated the PR title, but you may have to set the commit message yourself when merging.