MID-4186 placeholders for password panel fields

gui/admin-gui/src/main/java/com/evolveum/midpoint/gui/api/component/password/PasswordPanel.html

@@ -19,8 +19,8 @@
 <wicket:panel>
 	<span wicket:id="linkContainer" class="col-md-11"><span wicket:id="passwordSet"/><span wicket:id="passwordRemove"/> <span class="btn-group" style="float:right"><a href="#" wicket:id="changePasswordLink" class="btn btn-primary btn-xs"></a></span></span>
 	<div wicket:id="inputContainer" class="col-md-11">
-	    <input class="form-control input-sm" wicket:id="password1" type="password" autocomplete="new-password" about="password1"/>
-	    <input class="form-control input-sm" wicket:id="password2" type="password" autocomplete="new-password" style="margin-top: 5px;" about="password2"/>
+	    <input class="form-control input-sm" wicket:id="password1" wicket:message="placeholder:PasswordPanel.passwordPlaceholder" type="password" autocomplete="new-password" about="password1"/>
+	    <input class="form-control input-sm" wicket:id="password2" wicket:message="placeholder:PasswordPanel.repeatPasswordPlaceholder" type="password" autocomplete="new-password" style="margin-top: 5px;" about="password2"/>
 	</div>
     <div wicket:id="removeButtonContainer" class="col-md-1"><span class="btn-group" style="float:right"><a href="#" wicket:id="removePasswordLink" class="btn btn-primary btn-xs"></a></span></div>
 </wicket:panel>

gui/admin-gui/src/main/resources/localization/Midpoint.properties

@@ -2400,6 +2400,8 @@ passwordPanel.passwordChange=Change
 passwordPanel.passwordRemove=Remove
 passwordPanel.passwordSet=password is set
 passwordPanel.passwordRemoveLabel=password will be removed
+PasswordPanel.passwordPlaceholder=Password
+PasswordPanel.repeatPasswordPlaceholder=Repeat password
 past.ChangeType.ADD=Added
 past.ChangeType.DELETE=Deleted
 past.ChangeType.MODIFY=Modified