Better Handle Dead Accounts in Balances (#7843)

* Don't mutate storage when account is dead and should stay dead

* cargo run --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_balances --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/balances/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* more concrete storage noop

Co-authored-by: Parity Benchmarking Bot <[email protected]>