dApps-Staking chain-extension - Reworked Errors

[PierreOssun]

Before the chain extension returned Result<() DispatchError> but it was not possible to decode it on contract side (in a handy way). The appropriate way is to write to buffer when a value needs to be returned. When a Result should be returned it should be wrapped in a RetVal and decoded on the contract side. This way no scale decoding error can happen.

Check list

• [X] Updated Trait function Return type
• [X] Updated all return statements

[github-actions[bot]]

Package	Line Rate	Branch Rate	Health
chain-extensions/trait/src	0%	0%	❌
chain-extensions/types/dapps-staking/src	0%	0%	❌
frame/block-reward/src	96%	0%	✔
frame/pallet-xcm/src	80%	0%	➖
precompiles/utils/macro/tests	100%	0%	✔
chain-extensions/impls/dapps-staking/src	0%	0%	❌
precompiles/substrate-ecdsa/src	78%	0%	➖
precompiles/xcm/src	80%	0%	➖
frame/dapps-staking/src/pallet	90%	0%	✔
precompiles/assets-erc20/src	91%	0%	✔
primitives/xcm/src	88%	0%	✔
frame/collator-selection/src	89%	0%	✔
frame/vesting/src	87%	0%	✔
precompiles/sr25519/src	78%	0%	➖
frame/xc-asset-config/src	88%	0%	✔
precompiles/utils/macro/src	0%	0%	❌
frame/dapps-staking/src	94%	0%	✔
precompiles/utils/src	83%	0%	✔
precompiles/dapps-staking/src	95%	0%	✔
frame/custom-signatures/src	80%	0%	✔
precompiles/utils/src/data	72%	0%	➖
Summary	86% (8375 / 9766)	0% (0 / 0)	✔

Minimum allowed line rate is 60%