Stage: Customizable Banner Implementation

[MitchellShiell]

0 - Implement a customizable banner for stage

Expected deliverable: A stage banner component that inputs JSON and renders banners displayed at the top of the page.

The component should have three styles: Info, Warning, Critical

The component should be able to be declared:

A) using an env variable (ie. NEXT_PUBLIC_SYSTEM_ALERTS) that inputs a json object {title: info....} and renders a banner on the explorer page.

B) As a component on any given page with a JSON object used as a prop

Useful links

Existing Implementation: https://github.com/virusseq/portal-ui/blob/main/components/SystemAlerts/index.tsx
Stage Feature Branch: https://github.com/overture-stack/stage/tree/feature/bannerComponent
Docs: https://docs.overture.bio/docs/core-software/Stage/overview