Previews: Use WordPress-generated preview links

[spacedmonkey]

Summary

Add new field in the REST API for preview link that dashboard and editor can use instead of working it out in JS.

Relevant Technical Choices

To-do

User-facing changes

Testing Instructions

1. Login to admin.
2. Create a new story.
3. Add content to story.
4. Save a darft.
5. Press preview button.

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1. Login to admin.
2. Go to dashboard ( My stories ).
3. Hover over a story ( specially on a story that is set to draft or scheduled ).
4. Click on 3 dots.
5. Click on open in new tab.

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Fixes #5963

[github-actions]

Size Change: +2 B (0%)

Total Size: 1.37 MB

ℹ️ View Unchanged

Filename	Size	Change
assets/css/edit-story.css	876 B	0 B
assets/css/stories-dashboard.css	288 B	0 B
assets/css/web-stories-embed-block.css	615 B	0 B
assets/js/chunk-fonts-********************.js	44.5 kB	0 B
assets/js/chunk-web-stories-template-0-********************.js	11 kB	0 B
assets/js/chunk-web-stories-template-1-********************.js	11.3 kB	0 B
assets/js/chunk-web-stories-template-2-********************.js	10.9 kB	0 B
assets/js/chunk-web-stories-template-3-********************.js	10.5 kB	0 B
assets/js/chunk-web-stories-template-4-********************.js	12.7 kB	0 B
assets/js/chunk-web-stories-template-5-********************.js	7.12 kB	0 B
assets/js/chunk-web-stories-template-6-********************.js	10.2 kB	0 B
assets/js/chunk-web-stories-template-7-********************.js	10.1 kB	0 B
assets/js/chunk-web-stories-textset-0-********************.js	5.23 kB	0 B
assets/js/chunk-web-stories-textset-1-********************.js	6.79 kB	0 B
assets/js/chunk-web-stories-textset-2-********************.js	7.81 kB	0 B
assets/js/chunk-web-stories-textset-3-********************.js	15.3 kB	0 B
assets/js/chunk-web-stories-textset-4-********************.js	4.38 kB	0 B
assets/js/chunk-web-stories-textset-5-********************.js	5.64 kB	0 B
assets/js/chunk-web-stories-textset-6-********************.js	5.43 kB	0 B
assets/js/chunk-web-stories-textset-7-********************.js	10.3 kB	0 B
assets/js/edit-story.js	612 kB	-15 B (0%)
assets/js/stories-dashboard.js	470 kB	+17 B (0%)
assets/js/vendors~chunk-ffmpeg-********************.js	5.76 kB	0 B
assets/js/web-stories-activation-notice.js	74.3 kB	0 B
assets/js/web-stories-embed-block.js	17.6 kB	0 B

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[swissspidy]

Just tested and works great!

[swissspidy]

@spacedmonkey could you add some testing instructions for Claudio? When I tried it everything worked fine, but want to make sure no current flows are broken.

[spacedmonkey]

@spacedmonkey could you add some testing instructions for Claudio? When I tried it everything worked fine, but want to make sure no current flows are broken.

Done