Create new 'AavePosition' class

[hschickdevs]

• Will include several transactions we made using already existing functions
• For example, we deposit 1 ETH, and then borrow 1000USDT for the collateral we get for the deposit. These two transactions will be viewed as a position.
• In general, the deposit we made and next maybe one or multiple borrowing based on the collateral can be viewed as one position.
• One position will include at least 2 transaction. It is kind of like grouping and put transactions into different groups.

This new 'AavePosition' class will need to support nested Aave positions like the recursive borrowing strategy:

For example, we need to firstly deposit 10 ETH and then borrow 50% of the collateral value of AVAX, then deposit AVAX we borrow, and also borrow 50% of the collateral value we deposit for AVAX, keep borrowing and deposit we borrow to see how much is our final APY.
Regarding this, we may need to do a test calculation in excel then move to the code.

[hschickdevs]

This class could just be a container and handler for multiple 'AaveTrade' classes