Improve extra field error range

[RblSb]

Closes #11334

[kLabz]

I thought we usually covered both field name + field value for this kind of errors?

[RblSb]

I recently made duplicate field errors also like this.
Not sure if field: value range is better here, it will simplify field removal on ide side (probably not much with tokentree?), but it will make optional field name typos more verbose.

[Simn]

I think just the name is better because the value itself could also be multiple lines and all that.