Update inline spacing treatment, using modern CSS features

[felixhabib]

Taking advantage of modern CSS spacing features for a better dev experience. This change:

• Adds a small size to the spacing scale (6px) and increases medium spacing to 8px
• Converts all existing uses of medium spacing to small spacing
• Updates the Inline component to:
  • use gap for spacing,
  • use the space scale from sprinkles, and
  • include an alignY prop
• Replaces uses of horizontal padding with flex gap on inline elements (using the Inline component or CSS where appropriate)
• Uses a 3 column grid for keyboard shortcut key arrangement
• Replaces vertical padding in Frame Panel with Stack spacing

Using the changeset from https://github.com/seek-oss/playroom/pull/355 as this work is related.

[changeset-bot[bot]]

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Latest commit: 10453051acb05a362c29d6ed308acc258c39fec0

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes changesets to release 1 package

| Name | Type | | -------- | ----- | | playroom | Minor |

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