Site Title Block: Add alignment and tag level support

[apeatling]

Part of #21087

Description

Adds text alignment support to the Site Title block. This also adds support for changing the heading level or using a paragraph as the tagName, but does not expose this in the UI.

How has this been tested?

• Enable the site editor experiments.
• Open the site editor and insert a site title block if one does not exist.
• Confirm that adjusting the alignment of the site title block works in the editor and front end.

Screenshots

Types of changes

New feature.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[github-actions]

Size Change: +6.75 kB (0%)

Total Size: 1.12 MB

Filename	Size	Change
build/a11y/index.js	1.14 kB	+1 B
build/annotations/index.js	3.62 kB	-1 B
build/api-fetch/index.js	3.4 kB	+2 B (0%)
build/autop/index.js	2.83 kB	-1 B
build/block-directory/index.js	6.75 kB	+270 B (4%)
build/block-directory/style-rtl.css	892 B	+105 B (11%)	⚠️
build/block-directory/style.css	892 B	+105 B (11%)	⚠️
build/block-editor/index.js	106 kB	+624 B (0%)
build/block-editor/style-rtl.css	11.4 kB	+51 B (0%)
build/block-editor/style.css	11.4 kB	+50 B (0%)
build/block-library/editor-rtl.css	7.87 kB	-4 B (0%)
build/block-library/editor.css	7.87 kB	-3 B (0%)
build/block-library/index.js	127 kB	+1.01 kB (0%)
build/block-library/style-rtl.css	7.72 kB	+31 B (0%)
build/block-library/style.css	7.72 kB	+31 B (0%)
build/block-serialization-default-parser/index.js	1.88 kB	+1 B
build/block-serialization-spec-parser/index.js	3.1 kB	-1 B
build/blocks/index.js	48.2 kB	+9 B (0%)
build/components/index.js	193 kB	+3.22 kB (1%)
build/components/style-rtl.css	19.5 kB	+9 B (0%)
build/components/style.css	19.5 kB	+9 B (0%)
build/compose/index.js	9.31 kB	-4 B (0%)
build/core-data/index.js	11.4 kB	+11 B (0%)
build/data/index.js	8.46 kB	+30 B (0%)
build/date/index.js	5.47 kB	+4 B (0%)
build/deprecated/index.js	771 B	-1 B
build/dom/index.js	3.17 kB	+55 B (1%)
build/edit-navigation/index.js	8.25 kB	+61 B (0%)
build/edit-navigation/style-rtl.css	918 B	+61 B (6%)	🔍
build/edit-navigation/style.css	919 B	+63 B (6%)	🔍
build/edit-post/index.js	302 kB	-41 B (0%)
build/edit-site/index.js	15 kB	+871 B (5%)	🔍
build/edit-widgets/index.js	8.83 kB	-48 B (0%)
build/editor/index.js	44.7 kB	+74 B (0%)
build/element/index.js	4.65 kB	+1 B
build/format-library/index.js	7.72 kB	+8 B (0%)
build/html-entities/index.js	621 B	-1 B
build/keyboard-shortcuts/index.js	2.52 kB	+4 B (0%)
build/keycodes/index.js	1.94 kB	+1 B
build/list-reusable-blocks/index.js	3.12 kB	-2 B (0%)
build/media-utils/index.js	5.3 kB	+7 B (0%)
build/notices/index.js	1.79 kB	+1 B
build/nux/index.js	3.4 kB	+1 B
build/plugins/index.js	2.56 kB	-1 B
build/primitives/index.js	1.5 kB	+1 B
build/redux-routine/index.js	2.85 kB	-2 B (0%)
build/rich-text/index.js	14.8 kB	+13 B (0%)
build/server-side-render/index.js	2.68 kB	+5 B (0%)
build/url/index.js	4.06 kB	+39 B (0%)
build/viewport/index.js	1.85 kB	+10 B (0%)
build/wordcount/index.js	1.17 kB	+1 B

ℹ️ View Unchanged

Filename	Size	Change
build/blob/index.js	620 B	0 B
build/block-library/theme-rtl.css	684 B	0 B
build/block-library/theme.css	686 B	0 B
build/data-controls/index.js	1.29 kB	0 B
build/dom-ready/index.js	568 B	0 B
build/edit-post/style-rtl.css	5.43 kB	0 B
build/edit-post/style.css	5.43 kB	0 B
build/edit-site/style-rtl.css	2.96 kB	0 B
build/edit-site/style.css	2.96 kB	0 B
build/edit-widgets/style-rtl.css	2.4 kB	0 B
build/edit-widgets/style.css	2.4 kB	0 B
build/editor/editor-styles-rtl.css	425 B	0 B
build/editor/editor-styles.css	428 B	0 B
build/editor/style-rtl.css	4.26 kB	0 B
build/editor/style.css	4.27 kB	0 B
build/escape-html/index.js	733 B	0 B
build/format-library/style-rtl.css	502 B	0 B
build/format-library/style.css	502 B	0 B
build/hooks/index.js	2.13 kB	0 B
build/i18n/index.js	3.56 kB	0 B
build/is-shallow-equal/index.js	711 B	0 B
build/list-reusable-blocks/style-rtl.css	226 B	0 B
build/list-reusable-blocks/style.css	226 B	0 B
build/nux/style-rtl.css	616 B	0 B
build/nux/style.css	613 B	0 B
build/priority-queue/index.js	789 B	0 B
build/shortcode/index.js	1.7 kB	0 B
build/token-list/index.js	1.28 kB	0 B
build/warning/index.js	1.14 kB	0 B

_{compressed-size-action}

[apeatling]

Converting to WIP/draft to add font size and color support before review.

[mtias]

@apeatling I think we can add the alignments first and do the others separately, just to keep things leaner for review