Replace a ton of trivial #ifdefs with runtime checks

This one is big, but unless I missed something, should be all be
trivial.

scripted-diff with the following, then manually tweaked whatever needed:
```

if [ $# -ne 3 ]; then
    echo "Usage: $0 '<pattern>' '<replacement>' '<filename>'"
    exit 1
fi

pattern="$1"
replacement="$2"
filename="$3"

if [ ! -f "$filename" ]; then
    echo "Error: File $filename does not exist."
    exit 1
fi

sed -i '/'"$pattern"'/ {
    :loop
    $ !{
        N
        /'"$pattern"'.*\n.*#endif/ {
            s/'"$pattern"'/'"$replacement"'/
            s/#else/} else {/
            s/#endif/}/
            P
            D
        }
        /'"$pattern"'/ b loop
    }
}' "$filename"

echo "Replacement complete in $filename"
```

h/t to Grok2 for the sed command

Ja2/jascreens.cpp

@@ -48,6 +48,7 @@
 	#include "IniReader.h"
 
 #include "sgp_logger.h"
+#include <language.hpp>
 
 #define _UNICODE
 // Networking Stuff
@@ -331,7 +332,7 @@ UINT32 InitScreenHandle(void)
 
 	if ( ubCurrentScreen == 255 )
 	{
-	#ifdef ENGLISH
+	if( g_lang == i18n::Lang::en ) {
 		if( gfDoneWithSplashScreen )
 		{
 			ubCurrentScreen = 0;
@@ -341,9 +342,9 @@ UINT32 InitScreenHandle(void)
 			SetCurrentCursorFromDatabase( VIDEO_NO_CURSOR );
 			return( INTRO_SCREEN );
 		}
-	#else
+	} else {
 		ubCurrentScreen = 0;
-	#endif
+	}
 	}
 
 	if ( ubCurrentScreen == 0 )