chore: make deprecated field easy to find for Tracker (#16056)

These orderable fields cannot be annotated with Deprecated which is why we have this comment. Make
it easier for us in team tracker by prefixing it a TODO for team tracker.

dhis-2/dhis-web-api/src/main/java/org/hisp/dhis/webapi/controller/tracker/export/event/EventMapper.java

@@ -72,7 +72,10 @@ public interface EventMapper
           entry("enrollmentStatus", "enrollment.status"),
           entry("event", "uid"),
           entry("followUp", "enrollment.followUp"),
-          entry("followup", "enrollment.followUp"), // Deprecated 2.41
+          entry(
+              "followup",
+              "enrollment.followUp"), // TODO(tracker): Deprecated 2.41, making it a TODO so we
+          // tracker remember to remove this.
           entry("occurredAt", "occurredDate"),
           entry("orgUnit", "organisationUnit.uid"),
           entry("program", "enrollment.program.uid"),
@@ -93,7 +96,11 @@ public interface EventMapper
   @Mapping(target = "orgUnit", source = "organisationUnit.uid")
   @Mapping(target = "occurredAt", source = "occurredDate")
   @Mapping(target = "scheduledAt", source = "scheduledDate")
-  @Mapping(target = "legacyFollowUp", source = "enrollment.followup") // Deprecated 2.41
+  @Mapping(
+      target = "legacyFollowUp",
+      source =
+          "enrollment.followup") // TODO(tracker): Deprecated 2.41, making it a TODO so we tracker
+  // remember to remove this.
   @Mapping(target = "followUp", source = "enrollment.followup")
   @Mapping(target = "createdAt", source = "created")
   @Mapping(target = "createdAtClient", source = "createdAtClient")