File log messages have duplicate timestamps

[shameekganguly]

E.g. 2024-02-08T22:15:18.176363233) (2024-02-08T22:15:18.176405072) [GUI] [Dbg] [Gui.cc:340] GUI requesting list of world names. The server may be busy downloading resources. Please be patient.

Seems to be coming from appending datetime once here and again here.

[azeey]

It's not clear to me what the original intention was. If it's to add a timestamp for both the console output and the file log, then we can just replace

  Console::log() << "(" << common::systemTimeIso() << ") ";
  std::stringstream prefixString;

with

  std::stringstream prefixString;
  prefixString << "(" << common::systemTimeIso() << ") ";

because all of contents of prefixString will end up in both the console and the file log.

If our intention is to have the timestamp just in the file log, but not in the console, then we would need to remove the () in Console::Log(), so it will be:

  Console::log << "(" << common::systemTimeIso() << ") ";
  std::stringstream prefixString;
  ...