Migrate PHP imagick module check to new SetupCheck API

[come-nc]

• See Migrate remaining setup checks to new API #41364

Summary

Migrate PHP imagick module check to new SetupCheck API.
It is in the theming application as it was only tested when this application is enabled. I also merged the SVG support check in it to be consistent.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[come-nc]

• Check if the linked documentation page documents imagick module, otherwise fix documentation or change/remove link