Common string entry (#971)

* Common string entry

* Add lib/common/string_entry.cpp + return const string*

source/lib/rocprofiler-sdk/code_object/hsa/code_object.hpp

@@ -61,7 +61,7 @@ struct code_object
 
     bool                     beg_notified    = false;
     bool                     end_notified    = false;
-    std::string*             uri             = {};
+    const std::string*       uri             = nullptr;
     hsa_executable_t         hsa_executable  = {};
     hsa_loaded_code_object_t hsa_code_object = {};
     code_object_data_t       rocp_data       = common::init_public_api_struct(code_object_data_t{});

source/lib/rocprofiler-sdk/code_object/hsa/kernel_symbol.hpp

@@ -60,7 +60,7 @@ struct kernel_symbol
 
     bool                    beg_notified   = false;
     bool                    end_notified   = false;
-    std::string*            name           = {};
+    const std::string*      name           = nullptr;
     hsa_executable_t        hsa_executable = {};
     hsa_agent_t             hsa_agent      = {};
     hsa_executable_symbol_t hsa_symbol     = {};