refactor!: move WalletChangeSet to bdk_wallet and fix import paths

crates/wallet/Cargo.toml

@@ -25,7 +25,7 @@ bdk_file_store = { path = "../file_store", version = "0.13.0", optional = true }
 bip39 = { version = "2.0", optional = true }
 
 [features]
-default = ["std", "file_store"]
+default = ["std"]
 std = ["bitcoin/std", "bitcoin/rand-std", "miniscript/std", "bdk_chain/std"]
 compiler = ["miniscript/compiler"]
 all-keys = ["keys-bip39"]