Post Title Block: Add style attributes (#24246)

- Add support for text and background colors, line height, font size to the Post Title block.
- Fix an issue causing the `HeadingLevelDropdown` to move to the top of the page when changing the heading level.

packages/block-library/src/post-title/block.json

@@ -17,6 +17,11 @@
 	"supports": {
 		"html": false,
 		"lightBlockWrapper": true,
+		"__experimentalColor": {
+			"gradients": true
+		},
+		"__experimentalFontSize": true,
+		"__experimentalLineHeight": true,
 		"__experimentalSelector": {
 			"core/post-title/h1": "h1",
 			"core/post-title/h2": "h2",

packages/block-library/src/post-title/edit.js

@@ -43,6 +43,8 @@ export default function PostTitleEdit( {
 		return null;
 	}
 
+	const BlockWrapper = Block[ tagName ];
+
 	return (
 		<>
 			<BlockControls>
@@ -61,14 +63,13 @@ export default function PostTitleEdit( {
 					} }
 				/>
 			</BlockControls>
-			<Block
-				tagName={ tagName }
+			<BlockWrapper
 				className={ classnames( {
 					[ `has-text-align-${ textAlign }` ]: textAlign,
 				} ) }
 			>
 				{ post.title || __( 'Post Title' ) }
-			</Block>
+			</BlockWrapper>
 		</>
 	);
 }