Alerts: Use Solaris icons

[louismaximepiton]

Prerequisites

• I have searched for duplicate or closed feature requests
• I have read the contributing guidelines

Proposal

Use the Solaris icons for Alerts icons. It should be aligned with new UI Kit.

Motivation and context

For now, our Alert component use some Solaris modified icons to fit our needs in terms of spacings, design and bundle size.
But with the arrival of Web UI Kit v6, we now need to be aligned with it and it changes the rendering of alerts. We should starting from now use the Solaris icons to fit the design. (Following #2075 (comment))