DappsStaking bench improvements

[shunsukew]

Pull Request Summary Dapps Staking CurrentEra storage value is accessed by on_initialize hook at every block. That means current era value is available in overlay cache, thus we can ignore storage access from benchmarking.

New attribute macro #[pallet::whitelist_storage] registers Storage items to whitelists (which will be ignored in benchmarking), see more details https://github.com/paritytech/substrate/pull/12205.

This requires Astar repo updates too, but adding attribute can be done independently.

This PR fixes format issue as well cargo fmt, taplo fmt to pass merge blocking.

[github-actions[bot]]

Package	Line Rate	Branch Rate	Health
frame/dapps-staking/src/pallet	90%	0%	✔
precompiles/substrate-ecdsa/src	78%	0%	➖
frame/block-reward/src	85%	0%	✔
precompiles/utils/src	72%	0%	➖
chain-extensions/types/xvm/src	0%	0%	❌
frame/xc-asset-config/src	70%	0%	➖
precompiles/assets-erc20/src	73%	0%	➖
frame/pallet-xcm/src	65%	0%	➖
frame/dapps-staking/src	83%	0%	✔
precompiles/utils/macro/src	0%	0%	❌
precompiles/sr25519/src	79%	0%	➖
precompiles/xvm/src	94%	0%	✔
primitives/xcm/src	68%	0%	➖
chain-extensions/types/rmrk/src	0%	0%	❌
frame/pallet-xvm/src/pallet	34%	0%	❌
frame/pallet-xvm/src	11%	0%	❌
chain-extensions/types/dapps-staking/src	0%	0%	❌
chain-extensions/dapps-staking/src	0%	0%	❌
frame/custom-signatures/src	57%	0%	➖
chain-extensions/rmrk/src	0%	0%	❌
precompiles/utils/macro/tests	0%	0%	❌
frame/collator-selection/src	80%	0%	✔
precompiles/dapps-staking/src	93%	0%	✔
precompiles/xcm/src	84%	0%	✔
precompiles/utils/src/data	72%	0%	➖
chain-extensions/xvm/src	0%	0%	❌
Summary	60% (2577 / 4328)	0% (0 / 0)	➖

Minimum allowed line rate is 50%