Set asset as collateral

[MerlinEgalite]

Pull Request

Descrition

This PR covers the edge case related to the LTV = 0 described here among other issues.

What the PR is doing:

• implements a "hot fix" that allows the DAO to set as not collateral on both Morpho and Aave (first Morpho, then Aave, otherwise it reverts). The Aave part is only possible if Morpho's aggregated HF will be > 1 after the switch. The "hot fix" is needed to avoid breaking the whole Protocol when an asset is LTV=0 on Aave.
• after applying the "hot fix" users that still own the asset as collateral and have not applied the proper actions will incur into all the side effects of owning an LTV=0 asset on Morpho that are different compared to LT=0 on Aave. In this case the user's HF and LTV will be lowered (the asset is not counted at all as collateral) and they could get liquidated, could not be able to borrow (this is the same as on Aave, user's LTV is lowered) and could not be able to withdraw.
• the PR does not include a detailed explanation of how Morpho plans to handle the edge case of an LTV=0 asset or soon to become LTV=0 asset and what happens to users that do not follow the procedure (see point above) or what users should do before Morpho apply the "hot fix"

We are working on complementary remediations are not contract related such as:

• Aave governance monitoring
• Communication channel with BGD
• Banner or pop ups in the frontend to warn users
• Communications texts prepare in advanded to send to Discord, Twitter, etc.

Issue(s) fixed

This pull request:

• fixes Wrong check for asset liquidity data  #537
• fixes We must implement setAssetAsCollateral function to handle ltv to 0 #538
• fixes https://github.com/spearbit-audits/review-morpho-Aave-v3/issues/40
• fixes https://github.com/spearbit-audits/review-morpho-Aave-v3/issues/41
• fixes https://github.com/spearbit-audits/review-morpho-Aave-v3/issues/42

[MerlinEgalite]

I'm trying to fix the CI but this is quite long 🫠

[MathisGD]

Perfect
Waiting for #680 to approve