Cardano Updates

The other uses of `extra` are kept due to semantics of `withTempFile`.

This pull request adds dependency constraints to the
`cardano-balance-tx` package, as this package is a likely target for
releasing on CHaP.

We also remove the direct dependency on the `either` package, because
it's easy.

Mithril team published a security advisory, leading to version bumps.
This PR uses fixed versions. Note that it does not update genesis
verification key which is somewhat surprising but might be fine.

https://github.com/input-output-hk/mithril/security/advisories/GHSA-724h-fpm5-4qvr

There wasn't a `SECURITY.md` file in the repository which is quite
important for such a project. The policy just reuse existing security
advisories infrastructure provided by GitHub.

This pull request adds dependency constraints to the
`cardano-wallet-network-layer` library, as this package is a likely
target for releasing on CHaP.

We also remove the direct dependency on the `mtl` package, because it's
easy.

This pull request adds dependency constraints to the
`cardano-wallet-network-layer` library, as this package is a likely
target for releasing on CHaP.

We also remove the direct dependency on the `mtl` package, because it's
easy.