Guest user modal update

[ericokuma]

This PR addresses APP-668 by updating the Add guest users modal:

• Preselects the first project: If the organization has at least one project, the first project in the list is now preselected by default when the modal opens. This improves user experience by providing a sensible default.
• Keeps project access multi-select dropdown open: The project selection dropdown now remains open after selecting or deselecting options, allowing users to make multiple selections without re-opening the dropdown each time. This was achieved by switching to onCheckedChange for the dropdown items.

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes (APP-668)
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!

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Linear Issue: APP-668

 

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[AdityaHegde]

Unrelated to this PR but the inputs seem mismatched. The email input is larger than project and access level.

Also there is no check mark beside selection in access level. Lets do a follow up to fix this?