Introduce two new abilities for getting and setting SEO data for given posts

[leonidasmi]

Context

Summary

This PR can be summarized in the following changelog entry:

• Introduces two new Yoast SEO abilities for getting and setting SEO data for given posts.

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:

• Create a post with meaningful content and set its SEO data (title, meta description, social title, robots, SEO/readability score, etc.)
• Using our getting SEO data ability with REST API:
  • Run a GET request to /wp-json/wp-abilities/v1/abilities/yoast-seo/get-post-seo-data/run?input[id]=<POST_ID>
    • where <POST_ID> is the post ID
  • or run a GET request to /wp-json/wp-abilities/v1/abilities/yoast-seo/get-post-seo-data/run?input[permalink]=https://basic.wordpress.test/uncategorized/<POST_URL>
    • where <POST_URL> is the post's URL
  • or run a GET request to `/wp-json/wp-abilities/v1/abilities/yoast-seo/get-post-seo-data/run?input[title]=<POST_TITLE_KEYWORDS>
    • where <POST_TITLE_KEYWORDS> is keywords that exist in the post's title, separated by commas.
    • So, if you want to find the post that has a title like 10 ways to backpack across northern Europe, you can use 10 ways, backpack, northern Europe or any combination of that, to find your post
• Confirm that you get a result of an array with the post's SEO data, like:

[
    {
        "post_id": 712,
        "post_title": "10 ways to backpack across northern Europe",
        "permalink": "https://basic.wordpress.test/10-ways-backpack-across-northern-europe/",
        "post_type": "post",
        "post_status": "publish",
        "seo_title": null,
        "meta_description": "Backpacking across Europe can be an awesome experience, if you know some tips about it.",
        "focus_keyphrase": "backpacking across Europe",
        "canonical": null,
        "is_cornerstone": false,
        "noindex": null,
        "nofollow": false,
        "noimageindex": false,
        "noarchive": false,
        "nosnippet": false,
        "open_graph_title": null,
        "open_graph_description": null,
        "twitter_title": null,
        "twitter_description": null,
        "schema_page_type": null,
        "schema_article_type": null,
        "seo_score": "ok",
        "readability_score": "ok",
        "inclusive_language_score": "na"
    }
]

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:

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.
• This PR also affects Yoast SEO for Google Docs. I have added a changelog entry starting with [yoast-doc-extension], added test instructions for Yoast SEO for Google Docs and attached the Google Docs Add-on 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.
• I have run grunt build:images and committed the results, if my PR introduces or edits images or SVGs.

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 #