fix(ms2/selection-actions): removed fixed width

[FelipeTrost]

Summary

The fixed with in the component was causing it to be too wide, when there were few elements inside it:

I made the width adapt to the elements inside and added padding:

[github-actions[bot]]

✅ Successfully created Preview Deployment.

https://pr-303---ms-server-staging-c4f6qdpj7q-ew.a.run.app