Fixes the imports and other things particularly in aaveBorrow.js script.

[SyedAsadKazmi]

• Changed ethers import from ethers to hardhat package (as getContractAt is a function of ethers imported from hardhat).
• Uninstalled the ethers package to avoid version conflicts.
• Replaced { deployer } to [ deployer ] in the lvalue (or LHS) of await ethers.getSigners().
• In the borrow and repay function calls of lendingPool, changed the argument value of 1 (i.e., denoting the interestRateMode and rateMode in the borrow and repay functions respectively) to 2. For this, you can refer to the explanation in this post.