DAM ticket counterpart for MGNLUI-6061

Rich text doesn't show the button to select an image from the server 

Steps to reproduce

1. Go to Web resources app and edit the Text and Image component dialog (/mtk/dialogs/components/textImage.yaml). Add to the RichText field the snippet

   configJsFile: /.resources/ckeditor/config-magnolia.js
   

1. Still in Resources app, open for editing the file /ckeditor/config-magnolia.js

   definition = {
     alignment: false,
     images: true,
     lists: true,
     source: false,
     tables: true,
     colors: null,
     fonts: null,
     fontSizes: null
   }
   

1. Move to Pages app, and create a Text and Image component
2. Clic on the Image icon and check no button for selecting an image is show.

Expected results
On the step 4, a button is shown to show the available images on the server

Actual results
No button is shown so no image can be selected

Workaround
N/A

Development notes
Tho it's possible to show the button overriding the CSS styles, it still doesn't work. Clicking on  it doesn't perform any actions.