descriptors: add unit tests and test vectors for miniscript

This commit adds test vectors taken from
https://github.com/rust-bitcoin/rust-miniscript/blob/59ad2ed/src/miniscript/ms_tests.rs
to the miniscript implementation.

Co-authored-by: Oli <gugger@gmail.com>

Author: benma

descriptors/go.mod

@@ -4,15 +4,15 @@ go 1.25.0
 
 require (
 	github.com/btcsuite/btcd/address/v2 v2.0.0
+	github.com/btcsuite/btcd/btcec/v2 v2.5.0
+	github.com/btcsuite/btcd/chaincfg/v2 v2.0.0
+	github.com/btcsuite/btcd/chainhash/v2 v2.0.0
 	github.com/btcsuite/btcd/txscript/v2 v2.0.0
 	github.com/btcsuite/btcd/wire/v2 v2.0.0
 	github.com/stretchr/testify v1.10.0
 )
 
 require (
-	github.com/btcsuite/btcd/btcec/v2 v2.5.0 // indirect
-	github.com/btcsuite/btcd/chaincfg/v2 v2.0.0 // indirect
-	github.com/btcsuite/btcd/chainhash/v2 v2.0.0 // indirect
 	github.com/btcsuite/btclog v1.0.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/decred/dcrd/crypto/blake256 v1.1.0 // indirect