[Proposal] Increase AAVE capTier from cap4 to cap5 (30M -> 100M)

This proposal also appears on Balancer's forum.

After only 10 days being live, the liquidity on the Aave Balancer-based Safety Module has steadily grow up to ~$220M. Volume has also kept the pace of liquidity and during the last days, AAVE/WETH 80/20 is the pool with the highest daily volume across all Balancer. With more liquidity at stake, the rewards on the Aave Safety Module went down, but keeping in good levels of ~40% APY.

Taking into account the previous numbers, we propose to raise the liquidity mining cap from $30M (cap4) to $100M (cap5) for $AAVE, following the previous raise approved on Snapshot.