(impact: low) Ability to toggle/set icons in error banner component

[georgiatanasov147]

Prerequisites

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Description

Clarity's clr-alert has icons for each alert type, while the error-banner does not.
It would be great if the user can toggle the icons or set custom ones.

Impact

It would improve the component and its usage by not having to resort to clr-alert when an icon is needed.

Clarity:
https://clarity.design/angular-components/alert/api/

Components:
https://vmware.github.io/vmware-cloud-director-ui-components/errorBanner/example