[9.0] [a11y] Fix Title announcement, image flyout dashboards (#220027) (#221721)

# Backport

This will backport the following commits from `main` to `9.0`:
- [[a11y] Fix Title announcement, image flyout dashboards
(#220027)](#220027)

<!--- Backport version: 9.6.6 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

<!--BACKPORT [{"author":{"name":"Paulina
Shakirova","email":"paulina.shakirova@elastic.co"},"sourceCommit":{"committedDate":"2025-05-28T04:21:01Z","message":"[a11y]
Fix Title announcement, image flyout dashboards (#220027)\n\n##
Summary\n\nThis PR resolves [[Platform:Dashboards:DashboardEditMode] Add
image\npanel is
announced\nincorrectly](#215483)
issue.\nTested in Safari (Chrome still doesn't pronounce it correctly,
which is\na known issue confirmed by Eui team.)\n\n<img width=\"915\"
alt=\"Screenshot 2025-05-04 at 14 06
37\"\nsrc=\"https://github.com/user-attachments/assets/1c2fc8ae-1efc-49b7-ad0b-57eea4cf416c\"\n/>","sha":"641ee87cc1b54b18e9320767071118ca5205c80d","branchLabelMapping":{"^v9.1.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["Project:Accessibility","release_note:skip","Team:SharedUX","backport:all-open","a11y","v9.1.0"],"title":"[a11y]
Fix Title announcement, image flyout
dashboards","number":220027,"url":"https://github.com/elastic/kibana/pull/220027","mergeCommit":{"message":"[a11y]
Fix Title announcement, image flyout dashboards (#220027)\n\n##
Summary\n\nThis PR resolves [[Platform:Dashboards:DashboardEditMode] Add
image\npanel is
announced\nincorrectly](#215483)
issue.\nTested in Safari (Chrome still doesn't pronounce it correctly,
which is\na known issue confirmed by Eui team.)\n\n<img width=\"915\"
alt=\"Screenshot 2025-05-04 at 14 06
37\"\nsrc=\"https://github.com/user-attachments/assets/1c2fc8ae-1efc-49b7-ad0b-57eea4cf416c\"\n/>","sha":"641ee87cc1b54b18e9320767071118ca5205c80d"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v9.1.0","branchLabelMappingKey":"^v9.1.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/220027","number":220027,"mergeCommit":{"message":"[a11y]
Fix Title announcement, image flyout dashboards (#220027)\n\n##
Summary\n\nThis PR resolves [[Platform:Dashboards:DashboardEditMode] Add
image\npanel is
announced\nincorrectly](#215483)
issue.\nTested in Safari (Chrome still doesn't pronounce it correctly,
which is\na known issue confirmed by Eui team.)\n\n<img width=\"915\"
alt=\"Screenshot 2025-05-04 at 14 06
37\"\nsrc=\"https://github.com/user-attachments/assets/1c2fc8ae-1efc-49b7-ad0b-57eea4cf416c\"\n/>","sha":"641ee87cc1b54b18e9320767071118ca5205c80d"}}]}]
BACKPORT-->

Co-authored-by: Paulina Shakirova <paulina.shakirova@elastic.co>

Author: kibanamachine

src/platform/plugins/private/image_embeddable/public/components/image_editor/image_editor_flyout.tsx

@@ -122,7 +122,7 @@ export function ImageEditorFlyout(props: ImageEditorFlyoutProps) {
     <>
       <EuiFlyoutHeader hasBorder={true}>
         <EuiTitle size="s">
-          <h2>
+          <h2 id="image-editor-flyout-title">
             {isEditing ? (
               <FormattedMessage
                 id="imageEmbeddable.imageEditor.editImagetitle"

src/platform/plugins/private/image_embeddable/public/components/image_editor/open_image_editor.tsx

@@ -84,6 +84,7 @@ export const openImageEditor = async ({
         paddingSize: 'm',
         ownFocus: true,
         'data-test-subj': 'createImageEmbeddableFlyout',
+        'aria-labelledby': 'image-editor-flyout-title',
       }
     );