Steps to reproduce the issue

We have been working on GSD - Google Structured Data on our sites, and while trying to comply with the guidelines, we noticed that, even if itemprop="publisher" does exist in types.json (/libraries/src/Microdata/types.json), it is not implemented anywhere else.

Result : a recurring error when checking with Google structured data testing tool.

We found this recommendation on Google forums and it works (inserted in an article).

<div itemprop="publisher" itemscope itemtype="http://schema.org/Organization"> <p>© 2018 <span itemprop="name">My site name</span> All Rights Reserved.</p>
<div itemprop="logo" itemscope itemtype="https://schema.org/ImageObject"><meta itemprop="url" content="complete_url_to_the_image/logo.png"><meta itemprop="height" content="215"/><meta itemprop="width" content="730"/></div> 
</div>

Is there a specific reason why this "type(?)" has not been included in Joomla, in info_block.php for example.

NB : We had to exclude some native modules as well, in order to fully comply to Google structured data testing tool on a simple page.
NB 2 : A warning on mainEntityOfPage :
The mainEntityOfPage field is recommended. Please provide a value if available.
As it is only a warning, I'll leave this aside.