i18n: Standardize isRTL practices

[sirreal]

#20298 added an isRTL function to @wordpress/i18n. Use it throughout Gutenberg.

Description

How has this been tested?

Screenshots

Types of changes

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: -152 B (0%)

Total Size: 1.11 MB

Filename	Size	Change
build/a11y/index.js	1.14 kB	+1 B
build/block-editor/index.js	106 kB	-25 B (0%)
build/block-library/index.js	119 kB	-26 B (0%)
build/blocks/index.js	48.1 kB	+6 B (0%)
build/components/index.js	190 kB	-107 B (0%)
build/compose/index.js	9.32 kB	+1 B
build/data/index.js	8.43 kB	+5 B (0%)
build/date/index.js	5.47 kB	+1 B
build/deprecated/index.js	772 B	+1 B
build/edit-navigation/index.js	7.89 kB	+6 B (0%)
build/edit-post/index.js	302 kB	+3 B (0%)
build/edit-site/index.js	14.1 kB	+2 B (0%)
build/edit-widgets/index.js	8.88 kB	-1 B
build/editor/index.js	44.6 kB	-5 B (0%)
build/element/index.js	4.64 kB	-2 B (0%)
build/format-library/index.js	7.71 kB	-2 B (0%)
build/i18n/index.js	3.56 kB	+1 B
build/is-shallow-equal/index.js	710 B	-1 B
build/keyboard-shortcuts/index.js	2.51 kB	-2 B (0%)
build/media-utils/index.js	5.29 kB	+1 B
build/plugins/index.js	2.56 kB	-1 B
build/priority-queue/index.js	788 B	-1 B
build/redux-routine/index.js	2.85 kB	-2 B (0%)
build/rich-text/index.js	14.8 kB	-1 B
build/shortcode/index.js	1.69 kB	-1 B
build/token-list/index.js	1.28 kB	-1 B
build/url/index.js	4.02 kB	-1 B
build/viewport/index.js	1.84 kB	-2 B (0%)
build/warning/index.js	1.14 kB	+1 B

ℹ️ View Unchanged

Filename	Size	Change
build/annotations/index.js	3.62 kB	0 B
build/api-fetch/index.js	3.4 kB	0 B
build/autop/index.js	2.83 kB	0 B
build/blob/index.js	620 B	0 B
build/block-directory/index.js	6.48 kB	0 B
build/block-directory/style-rtl.css	787 B	0 B
build/block-directory/style.css	787 B	0 B
build/block-editor/style-rtl.css	11.3 kB	0 B
build/block-editor/style.css	11.3 kB	0 B
build/block-library/editor-rtl.css	7.61 kB	0 B
build/block-library/editor.css	7.61 kB	0 B
build/block-library/style-rtl.css	7.68 kB	0 B
build/block-library/style.css	7.68 kB	0 B
build/block-library/theme-rtl.css	684 B	0 B
build/block-library/theme.css	686 B	0 B
build/block-serialization-default-parser/index.js	1.88 kB	0 B
build/block-serialization-spec-parser/index.js	3.1 kB	0 B
build/components/style-rtl.css	19.5 kB	0 B
build/components/style.css	19.5 kB	0 B
build/core-data/index.js	11.4 kB	0 B
build/data-controls/index.js	1.29 kB	0 B
build/dom-ready/index.js	568 B	0 B
build/dom/index.js	3.11 kB	0 B
build/edit-navigation/style-rtl.css	857 B	0 B
build/edit-navigation/style.css	856 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/html-entities/index.js	622 B	0 B
build/keycodes/index.js	1.94 kB	0 B
build/list-reusable-blocks/index.js	3.12 kB	0 B
build/list-reusable-blocks/style-rtl.css	226 B	0 B
build/list-reusable-blocks/style.css	226 B	0 B
build/notices/index.js	1.79 kB	0 B
build/nux/index.js	3.4 kB	0 B
build/nux/style-rtl.css	616 B	0 B
build/nux/style.css	613 B	0 B
build/primitives/index.js	1.5 kB	0 B
build/server-side-render/index.js	2.68 kB	0 B
build/wordcount/index.js	1.17 kB	0 B

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[sirreal]

Superseded by #27838