Platform: analytics for Flourish embeds in body fields

[mariacha]

Coming out of #328 now any Flourish items that are Embeds have analytics, but if the Flourish item is embedded within the body, like https://es.wri.org/insights/el-financiamiento-climatico-es-la-historia-mas-importante-seguir-en-2025, flourish analytics do not show.

Dev tasks

• Create a custom filter that can be added to a "Text format". Africa has an example of one: https://github.com/wri/wri-africa/blob/main/web/modules/custom/wri_africa_entity_share/src/Plugin/Filter/RelToFlagshipAbs.php and you can use drush generate plugin:filter to create your own. Put it into the wri_media module.
• In the filter, look for if (strpos($embed_code, 'flourish-embed') !== FALSE) { to see if the body contains a flourish embed. If it does, add the script. You can move the if block that starts with if ($media && $media->hasField('field_media_embed_code')) { out of wri_media_preprocess_media and use it here.
• Add this filter to the "Full Html" and "Unrestricted text" formats and save those config changes back to web/profiles/contrib/wri_sites/modules/wri_media/config/install/editor.editor.full_html.yml and web/profiles/contrib/wri_sites/modules/wri_admin/config/install/filter.format.unrestricted_text.yml respectively.
• Create an update hook that sets the config from the last step across all IOs.