To retrieve and deploy Salesforce Messaging Components, ConversationMessageDefinition should be used.
package.xml:
<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
<types>
<members>*</members>
<name>ConversationMessageDefinition</name>
</types>
<version>59.0</version>
</Package>
