[ksp2] No API to get error type's name

[acejingbo]

When an type Foo is error type (unresolvable), there's no way to get API to get this error type's original name/code/text Foo.

Repro

acejingbo@8900934

See when you wrote NonExistType in code, no matter how you query you only get <ERROR TYPE: NonExistType> and cannot get the original name NonExistType. And the only way left if a hardcoded regex
"""<ERROR TYPE: ([\w\s\.]+)>""".toRegex().find(errorType.toString())?.destructured?.toList()?.first()