Site Title and Tagline: Add text decoration support

[aaronrobertshaw]

Related:

• Tracking: Addressing Design Tooling Consistency #43241
• Tracking: Typography Design Tools Consistency #43242

What?

Adds missing text-decoration block support to Site Title and Site Tagline blocks.

Why?

• Improves consistency of our design tools across blocks.

How?

• Opts into missing text-decoration typography support for Site Title and Site Tagline blocks.

Testing Instructions

1. Edit a post, add both a Site Title and Site Tagline block.
2. Select the Site Title block and ensure the text decoration control isn't displayed by default.
3. Confirm text decoration for the Site Title block works in both the editor and frontend.
4. Repeat steps 2-3 for the Site Tagline block.
5. Confirm that you can set text decoration in the global styles for both Site Title and Site Tagline.
6. Test that you can apply text decoration to both blocks via theme.json

Example theme.json snippet:

			"core/site-title": {
				"typography": {
					"textDecoration": "line-through"
				}
			},
			"core/site-tagline": {
				"typography": {
					"textDecoration": "line-through"
				}
			}

Screenshots or screencast

Screen.Recording.2022-09-08.at.7.35.59.pm.mp4

[glendaviesnz]

LGTM:

✅ Could add optional text decoration in post editor tools panel and changes were reflected in editor and frontend
✅ Could set text decoration in theme.json and reflected in editor and frontend