Log angular (reactive) forms field validation status to console

ng-debug (reactive) forms field validation

debugFormValidations(form: FormGroup) {
  Object.keys(form.controls).forEach(k => {
    const control = form.controls[k];
    // see https://angular.io/api/forms/AbstractControl#status
    const log = control.invalid ? console['warn'] : console['log'];
    log(k, 'invalid', control.invalid, 'value', control.value);
  });
}