Fixes an incompatibility with Gutenberg for position-based highlighting

[mhkuu]

Context

• We want to fix an incompatibility with the latest Gutenberg version (17.3.0) for position-based highlighting.

Summary

This PR can be summarized in the following changelog entry:

• Fixes a bug where highlighting for the keyphrase density assessment would not work when using the latest version of Gutenberg (17.3.0).

Relevant technical choices:

• Before Gutenberg 17.3.0, the HTML content could be retrieved by directly calling on the RichText block's attributes. Since Gutenberg 17.3.0, that returns a RichTextData object, from which we can retrieve the HTML through toString().
• Note that we can not use getBlockContent from @wordpress/blocks here, as the richTextIdentifier may differ per block (e.g., we only want to retrieve the caption from an image block, not the image itself).
• In this PR, I also updated some JSDoc, and renamed some variables -- so a little bit of boy scouting.

Test instructions

Test instructions for the acceptance test before the PR gets merged

This PR can be acceptance tested by following these steps:

With new Gutenberg

• Install and activate Free (with this PR) and Gutenberg (>= 17.3.0).
• Create a new post.
• Add the English text from Appendix A of the HTML Parser phase 2.2 ATP.
• Set the following keyword: Mahler.
• Make sure that the feedback for the keyphrase density says the following: Keyphrase density: The focus keyphrase was found 9 times. This is great!.
• Make sure that all 9 occurrences of the keyphrase are highlighted when pressing the highlighting button.
• Note that in the occurrence of Mahler that is followed by a dash, the word after the dash will also be highlighted (Mahler—who). This is known behavior.
• Change the keyphrase to: Gustav Mahler.
• Make sure that the feedback for the keyphrase density says the following: Keyphrase density: The focus keyphrase was found 2 times. This is great!
• Make sure that all 2 occurrences of the keyphrase are highlighted when pressing the highlighting button.
• Add an image block, set the caption to Gustav Mahler was an Austro-Bohemian Romantic composer. More on Gustav Mahler in this image..
• Make sure that the feedback for the keyphrase density says the following: Keyphrase density: The focus keyphrase was found 4 times. This is great!.
• Make sure that all 4 occurrences of the keyphrase are highlighted when pressing the highlighting button.

Without Gutenberg

• Keep Free (with this PR), but deactivate Gutenberg (so that we're using the version of Gutenberg coupled with WordPress 6.4.2).
• Repeat the above steps and verify everything works.

Relevant test scenarios

• Changes should be tested with the browser console open
• Changes should be tested on different posts/pages/taxonomies/custom post types/custom taxonomies
• Changes should be tested on different editors (Block/Classic/Elementor/other)
• Changes should be tested on different browsers
• Changes should be tested on multisite

Test instructions for QA when the code is in the RC

• QA should use the same steps as above.

QA can test this PR by following these steps:

Impact check

This PR affects the following parts of the plugin, which may require extra testing:

• The highlighting of the keyphrase density assessment in the default and Gutenberg editor.

UI changes

• This PR changes the UI in the plugin. I have added the 'UI change' label to this PR.

Other environments

• This PR also affects Shopify. I have added a changelog entry starting with [shopify-seo], added test instructions for Shopify and attached the Shopify label to this PR.

Documentation

• I have written documentation for this change.

Quality assurance

• I have tested this code to the best of my abilities.
• During testing, I had activated all plugins that Yoast SEO provides integrations for.
• I have added unit tests to verify the code works as intended.
• If any part of the code is behind a feature flag, my test instructions also cover cases where the feature flag is switched off.
• I have written this PR in accordance with my team's definition of done.
• I have checked that the base branch is correctly set.

Innovation

• No innovation project is applicable for this PR.
• This PR falls under an innovation project. I have attached the innovation label.
• I have added my hours to the WBSO document.

Fixes #21001

[coveralls]

Pull Request Test Coverage Report for Build b916859d6412f9f668afb94f29ae49ca5db20d6a

• 11 of 12 (91.67%) changed or added relevant lines in 2 files are covered.
• 1419 unchanged lines in 38 files lost coverage.
• Overall coverage decreased (-10.4%) to 38.833%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/js/src/decorator/helpers/searchBasedAnnotationHelper.js	5	6	83.33%

Files with Coverage Reduction	New Missed Lines	%
admin/class-option-tabs-formatter.php	1	0.0%
src/generated/assets/externals.php	1	0.0%
src/generated/assets/languages.php	1	0.0%
src/integrations/blocks/structured-data-blocks.php	1	15.5%
src/integrations/settings-integration.php	1	21.59%
admin/class-admin-editor-specific-replace-vars.php	2	85.71%
admin/formatter/class-metabox-formatter.php	2	82.29%
inc/class-wpseo-custom-fields.php	2	0.0%
inc/class-wpseo-utils.php	2	44.29%
inc/sitemaps/class-post-type-sitemap-provider.php	2	94.09%

Totals
Change from base Build 7345460417:	-10.4%
Covered Lines:	18872
Relevant Lines:	45398

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💛 - Coveralls