History entry for text class changes (#641894)

Changes to the text class of a case history entry are now documented in the case history. The corresponding history entry mentions the number of the entry whose text class was modified and the new text class. The action is also visible in the Recent Changes widget.

The visibility of these history entries is controlled by a new setting named Text class changed on the Case history page in the Web Admin Suite. By default, this setting is enabled for medium and high detail levels. You can adjust the visibility level in the new setting to match your requirements.