kilinkis

This plugin has the hability to change the title of all the images attached to a post by inserting a new title for them all.
The plugin lists the posts on a table which you can order by name or category and each row has an input field which applies (with ajax), the input value to the title of all the images attached to that post.
This plugin uses Matt Van Andel class (which extends WP_List_Table) to use official WordPress API to create the tables. 
I want to thank @nh3ad who helped me on this development.

Attached images title editor

This plugin has the hability to change the title of all the images attached to a post by inserting a new title for them all.

ska-dev

websevendev

jimedwards

This plugin adds additional advanced inspector controls to Gutenberg blocks that allow to add any custom HTML attributes to the block’s front-end output. This allows you to add inline styles to fine-tune the block’s appearance, set aria attributes to improve your site’s accessibility, add data attributes to integrate with any JavaScript modules or even JavaScript DOM event attributes such as <code>onclick</code>, <code>onchange</code> or <code>onload</code>.
<a href="https://playground.wordpress.net/?plugin=attributes-for-blocks&url=%2Fwp-admin%2Fpost.php%3Fpost%3D2%26action%3Dedit" rel="nofollow ugc">Demo</a>

Attributes for Blocks

It's perfect for what I need! I hope you'll keep it updated as this behaviour should really be native in WordPress!

This should be native!

This is just Gold

Allows to add HTML attributes to Gutenberg blocks.

Attached images title editor vs Attributes for Blocks