free5GC NRF: type-confusion panic in POST /oauth2/token structured-form parser via Reflect.Set on incompatible types

Summary free5GC's NRF root SBI endpoint POST /oauth2/token contains a parser-level type-confusion bug family. The handler in NFs/nrf/internal/sbi/apiaccesstoken.go reflects over models.NrfAccessTokenAccessTokenReq, special-cases only plain string and NrfNfManagementNfType fields, and treats every...