[TOOL IMPROVEMENT] JSON diff formatting large values

[roland-d]

Describe the solution you'd like
Today I tried the JSON diff and at first it looked like nothing had happened. After looking around I found out that the diff did actually happen but just the output was suboptimal. That happens because the JSON contains some large values and that pushes everything off screen.

Example first JSON:

{
  "phpSettings": {
    "disable_functions": "getmyuid,passthru,leak,listen,diskfreespace,tmpfile,link,ignore_user_abort,shell_exec,dl,set_time_limit,exec,system,highlight_file,source,show_source,fpassthru,virtual,posix_ctermid,posix_getcwd,posix_getegid,posix_geteuid,posix_getgid,posix_getgrgid,posix_getgrnam,posix_getgroups,posix_getlogin,posix_getpgid,posix_getpgrp,posix_getpid,posix_getppid,posix_getpwuid,posix_getrlimit,posix_getsid,posix_getuid,posix_isatty,posix_kill,posix_mkfifo,posix_setegid,posix_seteuid,posix_setgid,posix_setpgid,posix_setsid,posix_setuid,posix_times,posix_ttyname,posix_uname,proc_open,proc_close,proc_nice,proc_terminate,escapeshellcmd,ini_alter,popen,pcntl_exec,socket_accept,socket_bind,socket_clear_error,socket_close,socket_connect,symlink,posix_geteuid,ini_alter,socket_listen,socket_create_listen,socket_read,socket_create_pair,stream_socket_server",
    "display_errors": false,
    "file_uploads": true,
    "iconv": true,
    "magic_quotes_gpc": false,
    "max_input_vars": "1000",
    "mbstring": true,
    "open_basedir": "xxxxxx",
    "output_buffering": true,
    "register_globals": false,
    "safe_mode": false,
    "session.auto_start": "0",
    "session.save_path": "",
    "short_open_tag": false,
    "xml": true,
    "zip": true,
    "zlib": true
  }
}

Example second JSON:

{
  "phpSettings": {
    "disable_functions": "",
    "display_errors": false,
    "file_uploads": true,
    "iconv": true,
    "magic_quotes_gpc": false,
    "max_input_vars": "1000",
    "mbstring": true,
    "open_basedir": "",
    "output_buffering": true,
    "register_globals": false,
    "safe_mode": false,
    "session.auto_start": "0",
    "session.save_path": "",
    "short_open_tag": false,
    "xml": true,
    "zip": true,
    "zlib": true
  }
}

This is what I see as output:

Additional context
I understand the issue now, as it is because of the phpSettings node but it would be nice if we can take such long values into account.

These JSONs are part of a much larger JSON but made smaller to understand it easier.

[CorentinTh]

Related to #413