[stable8] fix(NcCheckboxRadioSwitch): ensure component has correct box sizing

[susnux]

☑️ Resolves

• Resolves NcCheckboxRadioSwitch wrong box-sizing #7187

On v9 this is fixed as all containers already have box-sizing: boder-box but on v8 we need to manually ensure this.

🏁 Checklist

• ⛑️ Tests are included or are not applicable
• 📘 Component documentation has been extended, updated or is not applicable
• 2️⃣ Backport to stable8 for maintained Vue 2 version or not applicable

[ShGKme]

We have many components without explicit box-sizing: boder-box. Maybe add it to all the components (except for large containers like modal, where we considered it a breaking change)?

[susnux]

Maybe add it to all the components (except for large containers like modal, where we considered it a breaking change)?

Makes sense but sounds like much work to adjust all components?

[ShGKme]

Makes sense but sounds like much work to adjust all components?

Waiting for an issue from every single component used outside the container, debugging again, and fixing box-sizing doing it one by one also doesn't sound like a small work to me