Merge bitcoindevkit/bdk#1395: Remove rand dependency from bdk

4bddb0de62 feat(wallet): add back TxBuilder finish() and sort_tx() with thread_rng() (Steve Myers)
45c0cae0a4 fix(bdk): remove rand dependency (rustaceanrob)

Pull request description:

  ### Description

  WIP towards removing `rand` fixes #871

  The `rand` dependency was imported explicitly, but `rand` is also implicitly used through the `rand-std` feature flag on `bitcoin`.

  ### Notes to he reviewers

  **Updated:**

  `rand` was used primarily in two parts of `bdk`. Particularly in signing and in building a transaction.

  Signing:
  - Used implicitly in [`sign_schnorr`](https://docs.rs/bitcoin/latest/bitcoin/key/struct.Secp256k1.html#method.sign_schnorr), but nowhere else within `signer`.

  Transaction ordering:
  - Used to shuffle the inputs and outputs of a transaction, the default
  - Used in the single random draw __as a fallback__ to branch and bound during coin selection. Branch and bound is the default coin selection option.

  See conversation for proposed solutions.

  ### Changelog notice

  - Remove the `rand` dependency from `bdk`

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

  #### New Features:

  * [x] I've added tests for the new feature
  * [x] I've added docs for the new feature

  #### Bugfixes:

  * [x] This pull request breaks the existing API
  * [x] I've added tests to reproduce the issue which are now passing
  * [x] I'm linking the issue being fixed by this PR

ACKs for top commit:
  ValuedMammal:
    ACK 4bddb0de62
  notmandatory:
    ACK 4bddb0de62

Tree-SHA512: 662d9bcb1e02f8195d73df16789b8c2aba8ccd7b37ba713ebb0bfd19c66163acbcb6f266b64f88347cbb1f96b88c8a150581012cbf818d1dc8b4437b3e53fc62

crates/wallet/tests/wallet.rs

@@ -24,6 +24,8 @@ use bitcoin::{
     absolute, transaction, Address, Amount, BlockHash, FeeRate, Network, OutPoint, ScriptBuf,
     Sequence, Transaction, TxIn, TxOut, Txid, Weight,
 };
+use rand::rngs::StdRng;
+use rand::SeedableRng;
 
 mod common;
 use common::*;
@@ -907,14 +909,15 @@ fn test_create_tx_absolute_high_fee() {
 #[test]
 fn test_create_tx_add_change() {
     use bdk_wallet::wallet::tx_builder::TxOrdering;
-
+    let seed = [0; 32];
+    let mut rng: StdRng = SeedableRng::from_seed(seed);
     let (mut wallet, _) = get_funded_wallet_wpkh();
     let addr = wallet.next_unused_address(KeychainKind::External);
     let mut builder = wallet.build_tx();
     builder
         .add_recipient(addr.script_pubkey(), Amount::from_sat(25_000))
-        .ordering(TxOrdering::Untouched);
-    let psbt = builder.finish().unwrap();
+        .ordering(TxOrdering::Shuffle);
+    let psbt = builder.finish_with_aux_rand(&mut rng).unwrap();
     let fee = check_fee!(wallet, psbt);
 
     assert_eq!(psbt.unsigned_tx.output.len(), 2);