make ParmParse prefixedName public

Src/Base/AMReX_ParmParse.H

@@ -1153,10 +1153,14 @@ public:
 
     static std::string ParserPrefix;
 
-protected:
-
+    /**
+     * \brief Prepend the prefix that this ParmParse object was constructed with to str.
+     * It is a run-time error if str is empty.
+     */
     [[nodiscard]] std::string prefixedName (const std::string_view& str) const;
 
+protected:
+
     std::string m_prefix; // Prefix used in keyword search
     std::string m_parser_prefix; // Prefix used by Parser
     Table* m_table;