use label method rather than getTitle

Problem/Motivation

method getTitle() is used for the title column in the table drag rows. Not every entity might have implemented getTitle() method, this may lead to WSOD for these entities

Steps to reproduce

use an entity that does not implement getTitle()

Proposed resolution

use label() method instead, which is required for every entity implementing EntityInterface: https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Entity%21...

Remaining tasks

provide patch

User interface changes

na

API changes

na

Data model changes

na