elf-util: Add support for parsing dlopen metadata

Then we can add support for showing dlopen metadata to systemd-analyze.

src/coredump/coredump-submit.c

@@ -689,7 +689,8 @@ int coredump_submit(
                                                 root,
                                                 /* fork_disable_dump= */ skip, /* avoid loops */
                                                 &stacktrace,
-                                                &json_metadata);
+                                                &json_metadata,
+                                                /* ret_dlopen_metadata= */ NULL);
                 }
         }