Make `TransactionExtension` tuple of tuple transparent for implication #9128

Job	Run time
preflight / preflight	34s
preflight / ci-versions	1m 4s
cargo-check-each-crate (1)	46m 24s
test-frame-ui	31m 26s
cargo-check-each-crate (2)	42m 13s
cargo-check-all-crate-macos	11m 58s
cargo-check-each-crate (3)	18m 31s
cargo-check-benches (master)	20m 59s
cargo-check-each-crate (4)	42m 42s
cargo-check-benches (current)	27m 24s
test-full-crypto-feature	2m 31s
cargo-check-each-crate (5)	52m 4s
test-node-metrics	14m 19s
cargo-check-each-crate (6)	24m 58s
cargo-check-each-crate (7)	47m 55s
test-frame-examples-compile-to-wasm	3m 0s
test-deterministic-wasm	8m 57s
check-tracing	2m 9s
check-metadata-hash	7m 54s
node-bench-regression-guard	12s
All test misc tests passed	1s
	6h 47m 15s

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