Snap to integer zoom level

[quinncnl]

Add an option to snap to integer zoom level: https://github.com/maplibre/maplibre-gl-js/issues/1591

Example: https://tracestrack.s3-website.nl-ams.scw.cloud/dist/ Example: https://tracestrack.s3-website.nl-ams.scw.cloud/dist/#12.40/11.7933/53.4402 jsfiddle: https://jsfiddle.net/142rftnx/1/

Launch Checklist

• [x] Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• [x] Briefly describe the changes in this PR.
• [x] Link to related issues.
• [ ] Include before/after visuals or gifs if this PR includes visual changes.
• [ ] Write tests for all new functionality.
• [x] Document any changes to public APIs.
• [ ] Post benchmark scores.
• [ ] Add an entry to CHANGELOG.md under the ## main section.