expose aave (helper) addresses

[Lukas]

Issue

Currently there's no easy way to figure out the aave addresses (aka there's no package one can import to get the currently up to date addresses). Also there's no easy way to get notified in case an address was updated.

What currently get's closest to this is:
https://github.com/aave/aave-addresses with jsons per network https://aave.github.io/aave-addresses/kovan.json

This is lacking helper contracts though as they are not registered at the protocol.

Proposed solution

For helper contracts I think it would be reasonable to have a static addresses = {[Network]: string} on the service so that people can simply access the address.

Alternative solution

We could also have a @aave/constants package or similar containing the addresses. This package could contain all the "generatable addresses" and all the helper contract addresses.

[Lukas]

apparently can only assign one person @sendra , @aschmidt20 , @joshstevens19 would appreciate feedback on this issue as it's along outstanding issue we should finally tackle imo.

[defispartan]

Definitely think this would be a nice package to add. This would be my suggestion for a schema:

core: { 
	lendingPoolAddressProvider: CoreContract
	lendingPoolAddressProviderRegistry: CoreContract
	LendingPool: CoreContract
	LendingPoolCollateralManager: CoreContract
	LendingPoolConfigurator: CoreContract
	LendingRateOracle: CoreContract
	PriceOracle: CoreContract
	PoolAdmin: CoreContract
	EmergencyAdmin: CoreContract
	ProtocolDataProvider: CoreContract
	WETHGateway: CoreContract
}

interface CoreContract{
	[Network]: {
		[Market] : string
	}
}

helpers: {
	walletBalanceProvider: HelperContract
	uiPoolDataProvider: HelperContract
	uiIncentiveDataProvider: HelperContract
}


interface HelperContract{
	[Network]: string
}

governance:  {
	AaveGovernanceV2: HelperContract
	ExecutorLong: HelperContract
	ExecutorShort: HelperContract
	ExecutorLowThresh: HelperContract
	GovernanceStrategy: HelperContract
	GovernanceV2Helper: HelperContract
}


tokens: {
	AAVE: ReserveToken
	AMPL: ReserveToken
	...
	YFI: ReserveToken
	ZRX: ReserveToken
}

interface ReserveToken{
	[Network]: {
		underlyingAssetAddress: string
		[Market]: {
			aTokenAddress: string
			variableDebtTokenAddress: string
			stableDebtTokenAddress: string
			interestRateStrategy: string
		}
	}
}

[sendra]

I think for this to be useful, it needs to be automated, taken directly from the blockchain, if not it will be again the same problem that we need to manually update it. at lest for the protocol addresses. For helpers maybe for now it could be hardcoded as we dont have any automated registry for them