Regroup SMLIGHT routers, add Nerivec silabs routers

[Nerivec]

Meant to be compatible with versions AFTER v2024.6.2-update3 (tagged with special app version to avoid conflict with manufacturer builds).

[Koenkk]

Thanks!

Could you also submit a picture for the docs? This can be done by:

1. Create a fork by clicking here
2. Go to the public/images/devices directory, Add file -> Upload files
3. Upload the files and press Commit changes
4. Press Contribute -> Open pull request -> update title/description -> Create pull request

Make sure that:

• The filename is Silabs-series-2-router.png
• The size is 512x512
• The background is transparent (use e.g. Adobe remove background)