refactor(wallet): cleanup and remove unused code in create_tx #1422

Job	Run time
prepare	4s
Check no_std	37s
Build & Test Examples (example_cli)	46s
Build and test (1.83.0, true, --no-default-features --features miniscript/no-std)	2m 43s
Check WASM	59s
Build & Test Examples (example_bitcoind_rpc_polling)	43s
Build and test (1.83.0, true, --all-features)	4m 22s
clippy_check	1m 15s
Build & Test Examples (example_electrum)	54s
Build and test (1.63.0, --no-default-features --features miniscript/no-std)	4m 30s
Build & Test Examples (example_esplora)	56s
Rust fmt	15s
Build and test (1.63.0, --all-features)	6m 14s
Build & Test Examples (example_wallet_electrum)	54s
Build & Test Examples (example_wallet_esplora_async)	1m 1s
Build & Test Examples (example_wallet_esplora_blocking)	54s
Build & Test Examples (example_wallet_rpc)	38s
	27m 45s

Provide feedback