[Feature] EVM precompiles to check hotkey's alpha stakes

[mateuszsrebrny-reef]

Is your feature request related to a problem? Please describe.

From within a smartcontract we would like to be able to access:

1️⃣ the hotkey's balance of alphas staked to a vali on a subnet
2️⃣ the list of valis a hotkey has alphas staked to on a subnet
3️⃣ the total of alphas staked by a hotkey to a subnet (derivable from 1 & 2)

I hear the first is easy, but still that would be useful: https://discordapp.com/channels/1120750674595024897/1242999357436071956/1351591677948596254

Describe the solution you'd like

I would like precompiles that can get me answer for all three questions :)
Whether it would be 3 precompiles or less but parametrized differently I don't really care.

Describe alternatives you've considered

No response

Additional context

No response

[keithtensor]

I am told that 1 is already implemented as getStake(), but 2 and 3 would require a bit more thought, specifically on what the inputs and outputs look like.

Regarding 2, it looks like it should be something like fn get_alpha_staked_validators(hotkey) -> Vec<Validator>, and 3 should look like fn total_alpha_staked(hotkey) -> TotalAlpha.

While 3 is derivable from 1 and 2, if the usage patterns of 3 is significant enough, I think it does make sense to make a separate precompiled function for it rather than to call 1 and 2 in order to derive 3.

[ppolewicz]

get_alpha_staked_validators and total_alpha_staked should accept not just hotkey as a parameter, but also netuid