chore: dedupe blob in consensus and rpc #1420

Job	Run time
doctest	1m 15s
clippy	34s
docs	1m 39s
feature-checks	2m 17s
fmt	11s
no-std	24s
wasm-unknown	46s
test stable --no-default-features	1m 19s
wasm-wasi	1m 5s
test stable	1m 24s
test stable --all-features	1m 43s
test nightly --no-default-features	1m 12s
test nightly	1m 23s
test nightly --all-features	1m 55s
test 1.76 --no-default-features	47s
test 1.76	39s
	18m 33s

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