Mark off-boarded collaterals on the dashboard

[aomafarag]

Goal

Off-boarded collaterals are marked as such on the dashboard

Context

Currently, collaterals listed on the dashboard have no indication whether they were off-boarded or not. We would like to mark the ones that were as such. A collateral is off-boarded when its debt ceiling (ilk.line) is set to 0.

Assets

• Our codebase
• MakerDAO docs: https://docs.makerdao.com/

Tasks

• Find a function in core to query a collateral's debt ceiling
• Use it to mark an off-boarded collateral as such on the dashboard