wip: working on extern in VM

- Feat: add writer externs writing fns
- Feat: add VM reader functions

src/vm/reader/vm_rd_extern_fns.c

@@ -0,0 +1,20 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <vm/fzl_vm_reader.h>
+#include <vm/internals/reader.h>
+
+// Read external functions definitions
+bool vm_rd_extern_fns(fzl_vm_reader_t *reader, FILE *fd)
+{
+  if (!reader || !fd)
+    return false;
+
+  uint16_t fns_count = reader->extern_fns_count;
+  if (!fns_count)
+    return true;
+
+  // TODO: fuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuck
+
+  return true;
+}