feat(mahalend): Add Mahalend app

[comandar21]

Description

We are adding Mahalend integration to zappe

Checklist

• [ x] I have followed the Contributing Guidelines
• (optional) As a contributor, my Ethereum address/ENS is:
• (optional) As a contributor, my Twitter handle is:

How to test?

[wpoulin]

You don't need to duplicate the aave-v2 abstract classes in /common

You can extend AaveV2LendingTokenFetcher and you won't need to copy pasta a bunch of files and abis.
Have a look how it's been done with aave-v2 src/apps/aave-v2/ethereum

[wpoulin]

Can't merge it just yet because of This branch is out-of-date with the base branch

Make sure to add remote upstream, pull master and push origin. Then the warning will disapear
@comandar21

[wpoulin]

We are closing Zapper Studio to new contributions. Instead, we'll be rolling out codeless app balance integrations, where folks can create integrations on Zapper's frontend (with no coding experience needed)

Here's the official announcement. I'll add mahalend to my todo since codeless app integrations aren't open to public just yet and I'll close this PR
Thanks for your contribution !