refactor(chain)!: update `TopologicalIter` to take an iterator #293

Job	Run time
Rust fmt	15s
prepare	3s
Check no_std	45s
Rust clippy	45s
Build & Test (1.88.0, true, --no-default-features --features miniscript/no-std,bdk_chain/hashbrown)	2m 6s
Build & Test (1.63.0, --no-default-features --features miniscript/no-std,bdk_chain/hashbrown)	8m 53s
Build & Test (1.63.0, --all-features)	9m 44s
Build & Test (1.88.0, true, --all-features)	3m 45s
Build & Test Examples (example_cli)	38s
Check WASM	2m 50s
Build & Test Examples (example_bitcoind_rpc_polling)	49s
Build & Test Examples (example_esplora)	57s
Build & Test Examples (example_electrum)	1m 1s
Build & Test (1.75.0, --no-default-features --features miniscript/no-std,bdk_chain/hashbrown)	2m 21s
Build & Test (1.75.0, --all-features)	4m 3s
	38m 55s

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