created call api in 2 steps

src/main/resources/db/changelog/db.changelog-1.0.0.xml

@@ -171,7 +171,6 @@
             <column name="submission_method" type="TEXT">
             </column>
             <column name="threshold" type="INTEGER">
-                <constraints nullable="false"/>
             </column>
             <column name="priority_area" type="TEXT"/>
             <column name="confidi" type="BOOLEAN"/>

src/main/resources/message_en.properties

@@ -43,6 +43,8 @@ call.created.successfully=Call created successfully.
 file.deleted.successfully=File deleted successfully.
 document.not.found=Document not found.
 document.id.not.found=Document ID not found.
+call.created.successfully=Call created successfully.
+call.invalid.date=Invalid start or end date.
 
 # Login-related messages
 login.successfully=Login successfully.

src/main/resources/message_it.properties

@@ -43,6 +43,7 @@ call.created.successfully=Chiamata creata correttamente.
 file.deleted.successfully=File eliminato con successo.
 document.not.found=Documento non trovato.
 document.id.not.found=ID documento non trovato.
+call.invalid.date=Data di inizio o fine non valida.
 
 # Login-related messages
 login.successfully=Accesso effettuato con successo.