Add v9's Combobox as combobox-multiple Select variant

[thure]

This PR also:

• upgrades to v9’s latest release
• fixes several visual regressions
• switches the single-combobox Select variant to v9’s new Dropdown
• improves testing for Select

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: 036ba8e1e89a1ace07df4c6c618ca925d75c5750

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

| Name | Type | | -------------------- | ----- | | @fluent-blocks/react | Minor |

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