feat(verify-attestation): RPC attestation and batch signature verification binary

This is another variant of the binary tool for verifying attestation and
the signature of a given batch. Unlike the existing tool, this variant
does not require you to provide two separate files—one for the
attestation and one for the signature. Instead, it automatically fetches
both from the RPC node.

Unfortunately, after discussing with @popzxc, we found that there is no way
to reuse the RPC client because our published crates on crates.io are
outdated and do not include the recently merged TEE-specific code
changes. To be fixed in the future.

shells/teepot/default.nix

@@ -9,6 +9,7 @@
 }:
 mkShell {
   inputsFrom = [ teepot.teepot ];
+
   packages = [
     dive
     taplo