alert: add tests for alert component

[JonasBa]

Just test the expanded state and icon, but I found that the expand button was not even a real button...

[codecov]

❌ 1 Tests Failed:

Tests completed	Failed	Passed	Skipped
8625	1	8624	3

View the top 1 failed test(s) by shortest run time

HighlightsIconSummary renders appropriate icons and text

Stack Traces | 0.175s run time

Error: expect(received).toHaveLength(expected)

Expected length: 2
Received length: 4
Received array:  [<img class="css-0" height="18px" src="[object Object]" width="18px" />, <img class="css-0" height="18px" src="[object Object]" width="18px" />, <svg fill="#71637E" height="14px" role="img" viewBox="0 0 16 16" width="14px"><path d="M14.77,16H1.23A1.26,1.26,0,0,1,0,14.75V6.52A1.25,1.25,0,0,1,1.23,5.27H14.77A1.25,1.25,0,0,1,16,6.52v8.23A1.26,1.26,0,0,1,14.77,16ZM1.48,14.5h13V6.77h-13Z" /><path d="M14.71,6h-1.5V4.14H2.79V6H1.29V3.89A1.25,1.25,0,0,1,2.54,2.64H13.46a1.25,1.25,0,0,1,1.25,1.25Z" /><path d="M13.37,3.39h-1.5V1.5H4.13V3.39H2.63V1.25A1.26,1.26,0,0,1,3.88,0h8.24a1.26,1.26,0,0,1,1.25,1.25Z" /></svg>, <svg fill="#71637E" height="14px" role="img" viewBox="0 0 16 16" width="14px"><path d="M13.25,16H2.75A2.75,2.75,0,0,1,0,13.25V2.75A2.75,2.75,0,0,1,2.75,0h10.5A2.75,2.75,0,0,1,16,2.75v10.5A2.75,2.75,0,0,1,13.25,16ZM2.75,1.5A1.25,1.25,0,0,0,1.5,2.75v10.5A1.25,1.25,0,0,0,2.75,14.5h10.5a1.25,1.25,0,0,0,1.25-1.25V2.75A1.25,1.25,0,0,0,13.25,1.5Z" /><rect height="1.5" width="14.5" x="0.75" y="4.62" /><circle cx="3.17" cy="3.18" r="0.76" /><circle cx="5.47" cy="3.18" r="0.76" /><circle cx="7.76" cy="3.18" r="0.76" /></svg>]
    at Object.<anonymous> (.../events/highlights/highlightsIconSummary.spec.tsx:108:61)

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