Include metadata in the API endpoints

[leonidasmi]

Context

Summary

This PR can be summarized in the following changelog entry:

• Includes metadata in the API endpoints about the time the query took to complete and whether cache was used.

Relevant technical choices:

Test instructions

Test instructions for the acceptance test before the PR gets merged

This PR can be acceptance tested by following these steps:

• Do a GET request to the /wp-json/yoast/v1/seo_scores?contentType=post endpoint
• Confirm that you now get a response similar to this:

{
    "scores": [
        {
            "name": "good",
            "amount": 1,
            "links": {
                "view": "http://example.com/wp-admin/edit.php?post_status=publish&post_type=post&seo_filter=good"
            }
        },
        {
            "name": "ok",
            "amount": 7,
            "links": {
                "view": "http://example.com/wp-admin/edit.php?post_status=publish&post_type=post&seo_filter=ok"
            }
        },
        {
            "name": "bad",
            "amount": 15,
            "links": {
                "view": "http://example.com/wp-admin/edit.php?post_status=publish&post_type=post&seo_filter=bad"
            }
        },
        {
            "name": "notAnalyzed",
            "amount": 82,
            "links": {
                "view": "http://example.com/wp-admin/edit.php?post_status=publish&post_type=post&seo_filter=na"
            }
        }
    ],
    "queryTime": 0.00069904327392578125,
    "cacheUsed": false
}

• Repeat the request within a minute and confirm that you get "queryTime": 0 and "cacheUsed": true
• Do the same for the /wp-json/yoast/v1/seo_scores?contentType=post&taxonomy=category&term=<TERM_ID> endpoint
• Do the same for the /wp-json/yoast/v1/readability_scores?contentType=post endpoint
• Do the same for the /wp-json/yoast/v1/readability_scores?contentType=post&taxonomy=category&term=<TERM_ID> endpoint
• Also, repeat tests for Create API endpoints for SEO and readability scores #21847

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 (Default Block/Gutenberg/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.

Impact check

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

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. For example, comments in the Relevant technical choices, comments in the code, documentation on Confluence / shared Google Drive / Yoast developer portal, or other.

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 https://github.com/Yoast/roadmap/issues/533

[coveralls]

Pull Request Test Coverage Report for Build 9fceeff4fdcba57800ba539c93ca6f137f114678

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 202 (0.0%) changed or added relevant lines in 24 files are covered.
• 993 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.04%) to 54.123%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/js/src/dashboard/scores/components/scores.js	0	1	0.0%
src/dashboard/user-interface/scores/abstract-scores-route.php	0	1	0.0%
src/dashboard/user-interface/scores/readability-scores-route.php	0	1	0.0%
src/dashboard/user-interface/scores/seo-scores-route.php	0	1	0.0%
src/dashboard/domain/score-groups/readability-score-groups/abstract-readability-score-group.php	0	2	0.0%
src/dashboard/domain/score-groups/seo-score-groups/abstract-seo-score-group.php	0	2	0.0%
src/dashboard/infrastructure/score-groups/score-group-link-collector.php	0	2	0.0%
src/dashboard/application/score-results/readability-score-results/readability-score-results-repository.php	0	3	0.0%
src/dashboard/application/score-results/seo-score-results/seo-score-results-repository.php	0	3	0.0%
src/dashboard/application/score-results/abstract-score-results-repository.php	0	7	0.0%

Files with Coverage Reduction	New Missed Lines	%
packages/js/src/dashboard/components/dashboard.js	2	0.0%
packages/js/src/dashboard/components/page-title.js	2	0.0%
packages/js/src/general/initialize.js	3	0.0%
src/generated/container.php	986	0.39%

Totals
Change from base Build b00849231c61562ca4cc281dd3302b5a0af57ce4:	-0.04%
Covered Lines:	29764
Relevant Lines:	55351

---

💛 - Coveralls

[thijsoo]

CR + ACC 👍