[RAO] Update staking precompile

[gztensor]

Staking precompile is implemented here:
https://github.com/opentensor/subtensor/blob/feat/evm-devnet-ready/runtime/src/precompiles/staking.rs
https://github.com/opentensor/subtensor/blob/feat/evm-devnet-ready/runtime/src/precompiles/solidity/staking.sol
https://github.com/opentensor/subtensor/blob/feat/evm-devnet-ready/runtime/src/precompiles/solidity/staking.abi

There are two things that need to happen for compatibility with rao:

• Right away: Update interface of add_stake and remove_stake methods so that it can accept netuid parameter and only accept root ID for now. Revert if netuid is not root.
• After rao is out: Respect netuid parameter and stake to the corresponding netuid.

For the second item, please base your changes on feat/rao-devnet-ready-2 and make the PR to it.