Provide a config setting option define number of images to be shown per page in the entity browser

Problem/Motivation:-
Currently in the media entity browser the number of images shown per page is limited to 12 by default.

Proposed Resolution:-
A configuration settings to be provided where the user can set this number of images to be shown per in the entity browser.

Tasks
✔ 1. Add a new form group to the DAM Settings page "Entity Browser Settings"
✔ 2. Add a numeric field to the form "Number of images per page"
✔ 3. Create a config setting in media_acquiadam.settings.settings.yml file and its default value to 12
num_images_per_page: 12
✔ 4. Via dependency injection call the config service in Entity browser plugin in Acquiadam.php file.
✔ 5. At this line number 236 call the config setting

// Number of assets to show per page.
    $num_per_page =12 

replace with

// Number of assets to show per page.
    $num_per_page = $config->get('num_images_per_page');