feat(precompile/staking): return full validators' description from queries

[Pitasi]

Description

• I enabled hardhat optimizations to reduce the code size (after my small change to IStaking, some tests contracts were exceeding the maximum allowed)
• Changed StakingI.sol to return the already existing Description struct instead of a string
• Recompiled all the contracts (here you'll see every single one is touched but my PR because of the optimizations)
• Fix gas usage expectation in one integration test for erc20, the gas consumed is reduces, probably because of the enabled optimization

Closes #629.

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I have...

• tackled an existing issue or discussed with a team member
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• targeted the main branch

[vladjdk]

Approved - really dislike the fact that the .jsons are in the codebase and not in .gitignore despite the fact that I myself removed them. Will probably add them back. Overall, though, thanks!