feat(radio-group): add helperText and errorText properties (#30222)

Issue number: N/A

---------

## What is the current behavior?
Radio group does not support helper and error text.

## What is the new behavior?
Adds support for helper and error text.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

## Other information

- [Supporting Text:
Preview](https://ionic-framework-git-rou-11554-ionic1.vercel.app/src/components/radio-group/test/supporting-text)

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Co-authored-by: Brandy Smith <6577830+brandyscarney@users.noreply.github.com>

packages/angular/common/src/directives/control-value-accessors/value-accessor.ts

@@ -52,6 +52,13 @@ export class ValueAccessor implements ControlValueAccessor, AfterViewInit, OnDes
     if (el === this.elementRef.nativeElement) {
       this.onTouched();
       setIonicClasses(this.elementRef);
+
+      // When ion-radio is blurred, el and this.elementRef.nativeElement are
+      // different so we need to check if the closest ion-radio-group is the same
+      // as this.elementRef.nativeElement and if so, we need to mark the radio group
+      // as touched
+    } else if (el.closest('ion-radio-group') === this.elementRef.nativeElement) {
+      this.onTouched();
     }
   }