Expanded DappStakingApi

[Dinonard]

Pull Request Summary

Extends the dApp staking runtime API with two additional calls:

• periods_per_cycle() - how many periods occur in a single inflation cycle
• get_dapp_tier_assignment() - returns dApps tier assignment based on the staked values at the called block

[github-actions]

Package	Line Rate	Branch Rate	Health
precompiles/dapps-staking/src	94%	0%	✔
pallets/dapp-staking-v3/rpc/runtime-api/src	0%	0%	❌
precompiles/xcm/src	72%	0%	➖
precompiles/assets-erc20/src	81%	0%	✔
pallets/dapps-staking/src/pallet	85%	0%	✔
pallets/dynamic-evm-base-fee/src	81%	0%	✔
pallets/xvm/src	40%	0%	❌
pallets/collator-selection/src	69%	0%	➖
pallets/dapp-staking-v3/src	76%	0%	➖
chain-extensions/pallet-assets/src	0%	0%	❌
precompiles/dapp-staking-v3/src	90%	0%	✔
precompiles/dapp-staking-v3/src/test	0%	0%	❌
pallets/dapp-staking-v3/src/benchmarking	0%	0%	❌
precompiles/unified-accounts/src	100%	0%	✔
pallets/static-price-provider/src	61%	0%	➖
precompiles/substrate-ecdsa/src	74%	0%	➖
pallets/inflation/src	70%	0%	➖
chain-extensions/xvm/src	0%	0%	❌
chain-extensions/types/unified-accounts/src	0%	0%	❌
primitives/src	66%	0%	➖
primitives/src/xcm	66%	0%	➖
pallets/ethereum-checked/src	48%	0%	❌
chain-extensions/types/xvm/src	0%	0%	❌
chain-extensions/unified-accounts/src	0%	0%	❌
pallets/xc-asset-config/src	53%	0%	➖
precompiles/xvm/src	74%	0%	➖
pallets/dapp-staking-migration/src	39%	0%	❌
pallets/unified-accounts/src	84%	0%	✔
pallets/dapp-staking-v3/src/test	0%	0%	❌
pallets/dapps-staking/src	81%	0%	✔
pallets/block-rewards-hybrid/src	87%	0%	✔
precompiles/sr25519/src	64%	0%	➖
chain-extensions/types/assets/src	0%	0%	❌
Summary	67% (3182 / 4739)	0% (0 / 0)	➖

Minimum allowed line rate is 50%

[shaunxw]

LGTM