Make pipeName be WideCStringObj so the data isn't deleted too early

[ire4ever1190]

Issue was brought up with nimlsp CI failing on windows

Investigating it led me to this section where pipeName was becoming garbage by the time it got to line 186. Looking at the arc expansion I saw the internal data was getting deleted too early

try:
  var number = 0'i64
  var pipeName: WideCString
  var pipeIn: Handle
  var pipeOut: Handle
  var sa = SECURITY_ATTRIBUTES(nLength: 24, lpSecurityDescriptor: nil,
                               bInheritHandle: 1)
  echo ["start loop"]
  block :tmp:
    while true:
      var
        p
        :tmpD_1
        :tmpD_2
      try:
        QueryPerformanceCounter(number)
        p = `&`(r"\\.\pipe\asyncpipe_") do:
          :tmpD_1 = $number
          :tmpD_1
        # Converter is called here which returns the raw data stored
        pipeName = toWideCString(
          :tmpD_2 = newWideCString(p)
          :tmpD_2)
        var openMode = 1074266113'i32
        var pipeMode = 0'i32
        pipeIn = createNamedPipe(pipeName, openMode, pipeMode, 1'i32, 65536'i32,
                                 65536'i32, 1'i32, addr(sa))
        if pipeIn == -1:
          let err = osLastError()
          if (
            not (int32(err) == 231)):
            raiseOSError(err, "")
        else:
          break :tmp
      finally:
        # Destroys the object which deallocs the data which
        # we are still using the pointer to
        `=destroy_1`(:tmpD_2)
        `=destroy`(:tmpD_1)
        `=destroy`(p)
  var openMode_1 = 1048578'i32

By keeping a reference to the actual object instead of the pointer inside, it doesn't get destroyed too early