logs: replace every fmt::print with a lg call instead (#1368)

Favors the `lg` namespace over `fmt` directly, as this will output the
logs to a file / has log levels.

I also made assertion errors go to a file, this unfortunately means
importing `lg` and hence `fmt` which was attempted to be avoided before.
But I'm not sure how else to do this aspect without re-inventing the
file logging.

We have a lot of commented out prints as well that we should probably
cleanup at some point / switch them to trace level and default to `info`
level.

I noticed the pattern of disabling debug logs behind some boolean,
something to consider cleaning up in the future -- if our logs were more
structured (knowing where they are coming from) then a lot this
boilerplate could be eliminated.

Closes #1358

common/cross_sockets/XSocketServer.cpp

@@ -12,6 +12,7 @@
 #include <WinSock2.h>
 #include <WS2tcpip.h>
 #endif
+#include "common/log/log.h"
 // clang-format on
 
 XSocketServer::XSocketServer(std::function<bool()> shutdown_callback,
@@ -67,19 +68,19 @@ bool XSocketServer::init_server() {
   addr.sin_port = htons(tcp_port);
 
   if (bind(listening_socket, (sockaddr*)&addr, sizeof(addr)) < 0) {
-    fmt::print("[XSocketServer:{}] failed to bind\n", tcp_port);
+    lg::error("[XSocketServer:{}] failed to bind", tcp_port);
     close_server_socket();
     return false;
   }
 
   if (listen(listening_socket, 0) < 0) {
-    fmt::print("[XSocketServer:{}] failed to listen\n", tcp_port);
+    lg::error("[XSocketServer:{}] failed to listen", tcp_port);
     close_server_socket();
     return false;
   }
 
   server_initialized = true;
-  fmt::print("[XSocketServer:{}] initialized\n", tcp_port);
+  lg::info("[XSocketServer:{}] initialized", tcp_port);
   post_init();
   return true;
 }