Airlock `AssetData` has unused variables

[clemlak]

Many variables in the Airlock AssetData struct are stored but never used onchain:

struct AssetData {
    address numeraire; // Never used onchain
    address timelock;
    address governance; // Never used onchain
    ILiquidityMigrator liquidityMigrator; 
    IPoolInitializer poolInitializer; // Never used onchain
    address pool; 
    address migrationPool; // Never used onchain
    uint256 numTokensToSell; // Never used onchain
    uint256 totalSupply; // Never used onchain
    address integrator;
}

I'm not sure how useful they are onchain and I feel like some of them could be removed.

[clemlak]

We'll take care of this in the next release.