Remove base64 dependency

We currently use `base64` to deserialize a vector. At the same time we
use `base64` indirectly from `rust-bitcoin` when deserializing a PSBT.

If we remove the dependency on `base64` and use the re-export from
bitcoin it saves having to keep the dependency and transient dependency
in sync so we don't get multiple versions of the same crate in the
dependency tree.

Author: tcharding

Cargo.toml

@@ -15,7 +15,6 @@ bitcoin = { version = "0.30.0", features = ["serde", "base64"] }
 serde = { version = "^1.0", features = ["derive"] }
 serde_json = { version = "^1.0" }
 pyo3 = { version = "0.15.1", features = ["auto-initialize"] }
-base64 = "0.13.0"
 
 miniscript = { version = "10.0", features = ["serde"], optional = true }
 

src/types.rs

@@ -3,6 +3,7 @@ use std::ops::Deref;
 use std::str::FromStr;
 
 use bitcoin::address::{Address, NetworkUnchecked};
+use bitcoin::base64;
 use bitcoin::bip32::{ExtendedPubKey, Fingerprint};
 use bitcoin::psbt::PartiallySignedTransaction;
 use bitcoin::Network;