issue a warning in legacy W10 terminals (PS/cmd)

Those terminal emulators block stdout/stderr output when scrolled,
which effectively stops UltraGrid. The behavior doesn't occur in MS
Terminal app, which is encouraged instead.

Note that Windows Terminal still runs cmd.exe or powershell.exe as a shell
while the cmd/PS process can acts like both terminal emulator and
shell. We also do not trigger the warning if UG is run from within
MSYS2 terminal.

src/host.cpp

@@ -116,6 +116,8 @@ extern "C" {
 #include <mcheck.h>
 #endif
 
+#define MOD_NAME "[host] "
+
 using std::array;
 using std::cout;
 using std::endl;
@@ -458,6 +460,16 @@ struct init_data *common_preinit(int argc, char *argv[])
         if (init_com) {
                 com_initialize(&init.com_initialized, nullptr);
         }
+
+        // warn in W10 "legacy" terminal emulators
+        if ((win_has_ancestor_process("powershell.exe") ||
+             win_has_ancestor_process("cmd.exe")) &&
+            !win_has_ancestor_process("WindowsTerminal.exe")) {
+                MSG(WARNING, "Running inside PS/cmd terminal is not recommended "
+                             "because scrolling the output freezes the process, "
+                             "consider using Windows Terminal instead!\n");
+                Sleep(1000);
+        }
 #endif
 
         if (strstr(argv[0], "run_tests") == nullptr) {