Refactor imports

Clean up some imports, only do the ones that we are about to touch.

- Remove/add whitespace to group by crate
- move modules/types to their module instead of using lib wide
  re-export (this helps minimise future merge conflicts)

Re-order imports, refactor only. No logic changes.

src/util/bip143.rs

@@ -9,15 +9,16 @@
 //! signatures, which are placed in the scriptSig.
 //!
 
+use core::ops::{Deref, DerefMut};
+
+use crate::io;
+
 use crate::hashes::Hash;
 use crate::hash_types::Sighash;
 use crate::blockdata::script::Script;
-use crate::blockdata::witness::Witness;
 use crate::blockdata::transaction::{Transaction, EcdsaSighashType};
+use crate::blockdata::witness::Witness;
 use crate::consensus::encode;
-
-use crate::io;
-use core::ops::{Deref, DerefMut};
 use crate::util::sighash;
 
 /// A replacement for SigHashComponents which supports all sighash modes

src/util/ecdsa.rs

@@ -5,12 +5,14 @@
 //!
 //! This module provides ECDSA signatures used Bitcoin that can be roundtrip (de)serialized.
 
-use crate::prelude::*;
 use core::str::FromStr;
 use core::{fmt, iter};
+
+use secp256k1;
+
+use crate::prelude::*;
 use crate::hashes::hex::{self, FromHex};
 use crate::blockdata::transaction::NonStandardSighashType;
-use secp256k1;
 use crate::EcdsaSighashType;
 use crate::internal_macros::write_err;
 

src/util/psbt/map/input.rs

@@ -2,17 +2,18 @@
 
 use crate::prelude::*;
 use crate::io;
+
 use core::fmt;
 use core::str::FromStr;
 use core::convert::TryFrom;
 
-use secp256k1;
+use secp256k1::XOnlyPublicKey;
+
 use crate::blockdata::script::Script;
 use crate::blockdata::witness::Witness;
 use crate::blockdata::transaction::{Transaction, TxOut, NonStandardSighashType, SighashTypeParseError};
 use crate::consensus::encode;
 use crate::hashes::{self, hash160, ripemd160, sha256, sha256d};
-use secp256k1::XOnlyPublicKey;
 use crate::util::bip32::KeySource;
 use crate::util::psbt;
 use crate::util::psbt::map::Map;
@@ -20,7 +21,6 @@ use crate::util::psbt::raw;
 use crate::util::psbt::serialize::Deserialize;
 use crate::util::psbt::{Error, error};
 use crate::util::key::PublicKey;
-
 use crate::util::taproot::{ControlBlock, LeafVersion, TapLeafHash, TapBranchHash};
 use crate::util::sighash;
 use crate::{EcdsaSighashType, SchnorrSighashType, EcdsaSig, SchnorrSig};