fix(radio): radios can be focused and are announced with group (#27817)

Issue number: resolves #27438

---------

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issue. -->

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

There are a few issues with the modern radio syntax:

1. The native radio is inside the Shadow DOM. As a result, radios are
not announced with their parent group with screen readers (i.e. "1 of
3")
2. The native radio cannot be focused inside of `ion-select-popover` on
Firefox.
3. The `ionFocus` and `ionBlur` events do not fire.

I also discovered an issue with item:

1. Items inside of a Radio Group have a role of `listitem` which prevent
radios from being grouped correctly in some browsers. According to
https://bugzilla.mozilla.org/show_bug.cgi?id=1840916, browsers are
behaving correctly here. The `listitem` role should not be present when
an item is used in a radio group (even if the radio group itself is
inside a list).

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

Most of the changes are test-related, but I broke it down per commit to
make this easier to review:


ae77002afd

- Item no longer has `role="listitem"` when used inside of a radio
group.
- Added spec tests to verify the role behavior


0a9b7fb91d

- I discovered that some the legacy basic test were accidentally using
the modern syntax. I corrected this by adding `legacy="true"` to the
radios.


a8a90e53b2,
412d1d54e7,
and
1d1179b69a

- The current radio group tests only tested the legacy radio syntax, and
not the modern syntax.
- I created a `legacy` directory to house the legacy syntax tests.
- I created new tests in the root test directory for the modern syntax.
- I also deleted the screenshots for the modern tests here because the
tests for `ion-radio` already take screenshots of the radio (even in an
item).


e2c966e68b
- Moved radio roles to the host. This allows Firefox to focus radios and
for screen readers to announce the radios as part of a group.
- I also added focus/blur listeners so ionFocus and ionBlur fire


f10eff47a5

- I cleaned up the tests here to use a common radio fixture

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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and migration path for existing applications below. -->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

I tested this with the following setups. ✅ indicates the screen reader
announces the group count (i.e. "1 of 4"). ❌ indicates the screen reader
does not announce the group count.

**Radio in Radio Group:**
- iOS + VoiceOver: ✅
- Android + TalkBack: ✅
- macOS + VoiceOver + Safari: ✅
- macOS + VoiceOver + Firefox: ✅
- macOS + VoiceOver + Chrome: ✅
- Windows + NVDA + Chrome: ✅
- Windows + NVDA + Firefox: ✅

**Radio in Item in Radio Group :**
- iOS + VoiceOver: ✅
- Android + TalkBack: ❌
(https://bugs.chromium.org/p/chromium/issues/detail?id=1459006)
- macOS + VoiceOver + Safari: ✅
- macOS + VoiceOver + Firefox: ✅
- macOS + VoiceOver + Chrome: ❌
(https://bugs.chromium.org/p/chromium/issues/detail?id=1459003)
- Windows + NVDA + Chrome: ✅
- Windows + NVDA + Firefox: ✅

core/src/components/item/item.tsx

@@ -398,7 +398,7 @@ export class Item implements ComponentInterface, AnchorInterface, ButtonInterfac
     });
     const ariaDisabled = disabled || childStyles['item-interactive-disabled'] ? 'true' : null;
     const fillValue = fill || 'none';
-    const inList = hostContext('ion-list', this.el);
+    const inList = hostContext('ion-list', this.el) && !hostContext('ion-radio-group', this.el);
 
     return (
       <Host

core/src/components/item/test/a11y/item.spec.ts

@@ -0,0 +1,51 @@
+import { Radio } from '../../../radio/radio.tsx';
+import { RadioGroup } from '../../../radio-group/radio-group.tsx';
+import { Item } from '../../item.tsx';
+import { List } from '../../../list/list.tsx';
+import { newSpecPage } from '@stencil/core/testing';
+
+describe('ion-item', () => {
+  it('should not have a role when used without list', async () => {
+    const page = await newSpecPage({
+      components: [Item],
+      html: `<ion-item>Hello World</ion-item>`,
+    });
+
+    const item = page.body.querySelector('ion-item');
+    expect(item.getAttribute('role')).toBe(null);
+  });
+
+  it('should have a listitem role when used inside list', async () => {
+    const page = await newSpecPage({
+      components: [Item, List],
+      html: `
+        <ion-list>
+          <ion-item>
+            Hello World
+          </ion-item>
+        </ion-list>
+      `,
+    });
+
+    const item = page.body.querySelector('ion-item');
+    expect(item.getAttribute('role')).toBe('listitem');
+  });
+
+  it('should not have a role when used inside radio group and list', async () => {
+    const page = await newSpecPage({
+      components: [Radio, RadioGroup, Item, List],
+      html: `
+        <ion-list>
+          <ion-radio-group value="a">
+            <ion-item>
+              <ion-radio value="other-value" aria-label="my radio"></ion-radio>
+            </ion-item>
+          </ion-radio-group>
+        </ion-list>
+      `,
+    });
+
+    const item = page.body.querySelector('ion-item');
+    expect(item.getAttribute('role')).toBe(null);
+  });
+});