fix: replace strncpy with memcpy and increase error message buffer size

Replace strncpy with memcpy in readBuiltInModule to avoid potential string termination issues
when copying module source code, and increase ERROR_MESSAGE_SIZE from 60 to 80 to provide
more room for compiler error messages with long variable names.

src/cli/modules.c

@@ -241,7 +241,7 @@ char* readBuiltInModule(const char* name)
 
   size_t length = strlen(*module->source);
   char* copy = (char*)malloc(length + 1);
-  strncpy(copy, *module->source, length + 1);
+  memcpy(copy, *module->source, length + 1);
   return copy;
 }