fix(admin-ui): Fixed DropdownMenu inside a Modal zIndex issues

[adevinwild]

Related issue

This PR is related to this issue #8158

What

This PR make sure to render the DropdownMenu in a React Portal to solves any issues when you have a DropdownMenu inside a Modal

• This is a common issue with RadixUI the solution is to use a Portal to make sure the DropdownMenu is rendered on the document.body instead of the same container
• Updated the zIndex from z-30 to z-50

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Latest commit: 8f0dd0d

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[kasperkristensen]

LGTM, thanks @adevinwild