[TASK] Adjust priority for handling link to extension documentation
Query the URL to the documentation from the Composer information (support.doc) and store the value in the database if it corresponds to a valid URL. Check whether the URL is valid on each output.
Adjust the order of the sources of the documentation URL as specified:
- composer.json documentation link (support.doc)
- documentation link from extension record
- documentation link from documentation.json
- no documentation link
Closes #640