Add RICH messaging pointer assert checks

Rich/RichFutureDAQ/RichFutureDAQ/RichPDMDBDecodeMapping.h

@@ -191,7 +191,10 @@ namespace Rich::Future::DAQ {
 
   private:
     /// Define the messenger entity
-    inline auto messenger() const noexcept { return m_parent; }
+    inline auto messenger() const noexcept {
+      assert( m_parent );
+      return m_parent;
+    }
 
   private:
     // data

Rich/RichFutureDAQ/RichFutureDAQ/RichPDMDBEncodeMapping.h

@@ -190,7 +190,10 @@ namespace Rich::Future::DAQ {
 
   private:
     /// Define the messenger entity
-    inline auto messenger() const noexcept { return m_parent; }
+    inline auto messenger() const noexcept {
+      assert( m_parent );
+      return m_parent;
+    }
 
   private:
     // data

Rich/RichFutureDAQ/RichFutureDAQ/RichTel40CableMapping.h

@@ -236,7 +236,10 @@ namespace Rich::Future::DAQ {
 
   private:
     /// Define the messenger entity
-    inline auto messenger() const noexcept { return m_parent; }
+    inline auto messenger() const noexcept {
+      assert( m_parent );
+      return m_parent;
+    }
 
   private:
     // data