feat: Print []+[] as Bool and [] as Unit in user-facing messages #2837

Job	Run time
Check for changes	4s
check	1m 29s
Build benchmarks 🏋️	2m 33s
tests (Rust 1.75)	2m 42s
tests (Rust beta)	2m 59s
tests (Rust stable, all features)	1m 46s
tests (Rust stable, no features)	1m 16s
tests (Rust nightly, coverage)	5m 8s
tests hugr-llvm	0s
Check standard extensions	6s
Required checks 🦀	1s
	18m 4s

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