Use <nlohmann/json.hpp> for replace deprecated <swss/json.hpp>

* [saidump]
• Saidump for DNX-SAI sonic-net/sonic-buildimage#13561

Solution and modification:
To use the Redis-db SAVE option to save the snapshot of DB each time and recover later, instead of looping through each entry in the table and saving it.

(1) Updated platform/broadcom/docker-syncd-brcm-dnx/Dockerfile.j2, install Python library rdbtools into the syncd containter.
(2) Updated sonic-buildimage/src/sonic-sairedis/saidump/saidump.cpp, add a new option -r, which updates the rdbtools's output-JSON files' format.
(3) Updated sonic-buildimage/build_debian.sh, to add a new script file: files/scripts/saidump.sh into the host. This shell file does the below steps:
  For each ASIC0, such as ASIC0,

  1. Save the Redis data.
  sudo sonic-db-cli -n asic$1 SAVE > /dev/null

  2. Move dump files to /var/run/redisX/
  docker exec database$1 sh -c "mv /var/lib/redis/dump.rdb /var/run/redis$1/"

  3. Run rdb command to convert the dump files into JSON files
  docker exec syncd$1 sh -c "rdb --command json /var/run/redis$1/dump.rdb | tee /var/run/redis$1/dump.json > /dev/null"

  4. Run saidump -r to update the JSON files' format as same as the saidump before. Then we can get the saidump result in standard output.
  docker exec syncd$1 sh -c "saidump -r /var/run/redis$1/dump.json -m 100"

  5. clear
  sudo rm -f /var/run/redis$1/dump.rdb
  sudo rm -f /var/run/redis$1/dump.json

(4) Update sonic-buildimage/src/sonic-utilities/scripts/generate_dump, to check the asic db size and if it is larger than xxx entries, then do with REDIS SAVE, otherwise, to do with old method: looping through each entry of Redis DB.

saidump/saidump.cpp

@@ -14,7 +14,7 @@ extern "C" {
 #include "swss/table.h"
 #include "meta/sai_serialize.h"
 #include "sairediscommon.h"
-#include "swss/json.hpp"
+#include <nlohmann/json.hpp>
 
 #include <getopt.h>
 
@@ -125,7 +125,7 @@ CmdOptions handleCmdLine(int argc, char **argv)
                 }
 
                 options.rdbJSonSizeLimit = result * 1024 * 1024;
-                SWSS_LOG_NOTICE("Configure the RDB JSON MAX size to %llu MB", options.rdbJSonSizeLimit / 1024 / 1024);                    
+                SWSS_LOG_NOTICE("Configure the RDB JSON MAX size to %llu MB", options.rdbJSonSizeLimit / 1024 / 1024);
 
                 break;
 
@@ -467,7 +467,7 @@ static sai_status_t preProcessFile(const std::string file_name)
     uint64_t file_size = input_file.tellg(); // Get the current position
 
     if (file_size >= g_cmdOptions.rdbJSonSizeLimit)
-    {        
+    {
         SWSS_LOG_ERROR_AND_STDERR("Get %s's size failure or its size %ld  >= %ld MB.", file_name.c_str(), file_size, g_cmdOptions.rdbJSonSizeLimit / 1024 / 1024);
         return SAI_STATUS_FAILURE;
     }
@@ -583,11 +583,11 @@ static sai_status_t dumpFromRedisRdbJson(const std::string file_name)
         return SAI_STATUS_SUCCESS;
     }
     catch (std::exception &ex)
-    {        
+    {
         SWSS_LOG_ERROR_AND_STDERR("JSON file %s is invalid.", file_name.c_str());
         SWSS_LOG_ERROR_AND_STDERR("JSON parsing error: %s.", ex.what());
     }
-        
+
     return SAI_STATUS_FAILURE;
 }