Import finalizer logic from miniscript

Import the `psbt` module from `rust-miniscript` while tip of master was:

  a280447 Merge rust-bitcoin/rust-miniscript#617: Improve `TapTree` API

Only do changes required to get things building, however this includes
upgrade of the bitcoin dependency.

Feature gate the miniscript stuff because we want this crate to be a
drop in replacement for the `psbt` module in `rust-bitcoin`, users may
not want to have `rust-miniscript` in there dependency tree.

Cargo.toml

@@ -22,9 +22,15 @@ no-std = ["bitcoin/no-std", "core2"]
 serde = ["actual-serde", "bitcoin/serde"]
 base64 = ["bitcoin/base64"]
 
+# TODO: There is curently no way to turn on miniscript/serde and base64
+miniscript-std = ["std", "miniscript/std"]
+miniscript-no-std = ["no-std", "miniscript/no-std"]
+
 [dependencies]
 bitcoin = { version = "0.31.0", default-features = false, features = [] }
 
+# Consider using "miniscript-std" or "miniscript-no-std"
+miniscript = { version = "10.0.0", default-features = false, optional = true }
 # Do NOT use this as a feature! Use the `serde` feature instead.
 actual-serde = { package = "serde", version = "1.0.103", default-features = false, features = [ "derive", "alloc" ], optional = true }
 # There is no reason to use this dependency directly, it is activated by the "no-std" feature.
@@ -35,3 +41,7 @@ serde_json = "1.0.0"
 serde_test = "1.0.19"
 serde_derive = "1.0.103"
 bincode = "1.3.1"
+secp256k1 = { version = "0.28", features = ["rand-std", "global-context"] }
+
+[patch.crates-io.miniscript]
+path = "../../rust-miniscript/dev-psbt"

src/lib.rs

@@ -35,6 +35,10 @@ extern crate actual_serde as serde;
 /// Re-export of the `rust-bitcoin` crate.
 pub extern crate bitcoin;
 
+/// Re-export of the `rust-bitcoin` crate.
+#[cfg(feature = "miniscript")]
+pub extern crate miniscript;
+
 mod error;
 #[macro_use]
 mod macros;