Refactor `pallet-grandpa` to use `v2` benchmarks #4473

Job	Run time
preflight / preflight	35s
preflight / preflight	35s
preflight / ci-versions	1m 16s
preflight / ci-versions	1m 16s
test-frame-ui	15m 13s
test-frame-ui	46m 21s
cargo-check-benches (master)	20m 3s
cargo-check-benches (master)	20m 3s
test-node-metrics	9m 36s
test-node-metrics	9m 36s
cargo-check-benches (current)	23m 15s
cargo-check-benches (current)	23m 15s
cargo-check-each-crate (1)	22m 39s
cargo-check-each-crate (1)	22m 39s
test-full-crypto-feature	2m 44s
test-full-crypto-feature	2m 44s
cargo-check-each-crate (2)	20m 20s
cargo-check-each-crate (2)	20m 20s
cargo-check-each-crate (3)	7m 28s
cargo-check-each-crate (3)	7m 28s
cargo-check-each-crate (4)	20m 8s
cargo-check-each-crate (4)	20m 8s
cargo-check-each-crate (5)	27m 51s
cargo-check-each-crate (5)	27m 51s
cargo-check-all-crate-macos	10m 41s
cargo-check-all-crate-macos	10m 41s
cargo-check-each-crate (6)	14m 34s
cargo-check-each-crate (6)	14m 34s
cargo-check-each-crate (7)	31m 12s
cargo-check-each-crate (7)	31m 12s
test-frame-examples-compile-to-wasm	3m 12s
test-frame-examples-compile-to-wasm	3m 12s
check-tracing	2m 18s
check-tracing	2m 18s
test-deterministic-wasm	7m 49s
test-deterministic-wasm	7m 49s
check-metadata-hash	7m 4s
check-metadata-hash	7m 4s
node-bench-regression-guard	13s
node-bench-regression-guard	13s
All test misc tests passed	1s
All test misc tests passed	1s
	8h 47m 32s

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