Fixes #15748: Prevent Rust panic during nested control flow compose()

[gitHazik]

Fixes #15748.
While running some fuzzing tests on compose(), I hit a hard Rust panic (called Option::unwrap() on a None value) in dag_circuit.rs. It gets triggered when composing circuits with nested control flow (like an if_test inside another if_test).

What changed:
I replaced the .unwrap() calls inside DAGCircuit::additional_wires (specifically the wires_from_expr closure) with .ok_or_else(). Now, instead of hard-crashing the Python interpreter, it safely raises a ValueError indicating a corrupted circuit state/mapping failure. I also added a regression test for this.

Note on the root cause:
I tracked the actual mapping bug down to CircuitData::native_extend in circuit_data.rs. When copying over other.blocks, it just clones them directly instead of recursively mapping the inner qubits and clbits. It also fails to update the stale bit references inside the expr::Expr conditions of ControlFlow ops, which is what ultimately triggers the None lookup in the DAG builder.

Since the classical expression engine is actively being rewritten in Rust right now, I figured it was safer to just catch the panic here and fail gracefully rather than trying to rewrite the AST traversal and causing massive merge conflicts with your ongoing work.

i used chatgpt to generate this description to explain better what i did

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