Enhancement: Add keyboard support to slide button

[jkaltoft]

Which issue does this PR close?

This PR closes #3605

What is the new behavior?

Slide Button will listen for keyboard events, specifically the arrow keys, page up/down keys and the Home and End keys

When receiving keyboard focus a focus ring will be applied (visually) to the slider thumb.

Does this PR introduce a breaking change?

• Yes
• No

Are there any additional context?

Checklist:

The following tasks should be carried out in sequence in order to follow the process of contributing correctly.

Reminders

• Make sure you have implemented tests following the guidelines in: "The good: Test".
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Review

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• Request that the changes are code-reviewed
• Request that the changes are UX reviewed (only necessary if your PR introduces visual changes)

When the pull request has been approved it will be merged to develop by Team Kirby.

[Fuzzy3]

Really nice - plain and simple solution! I would like to have a UX' opinion on the "speed" of the sliding when using the keyboard. I would prefer to have it a little "faster"