How to manipulate OroCRM grid using event listener

You may face with the situation when it is necessary to change a data grid for your OroCRM application. It is quite easy if you have already created your own bundle (we’ve described how to create a bundle in the previous article).
In this case, you can simply add few changes to datagrid.yml of this bundle. Nevertheless, sometimes we have to work with the bundles created by other developers or system bundles. And in those cases, we can use two ways: overwrite a full data grid configuration of the corresponded bundle or work with events of a listener.