Cyrpto future used margin vs maintenance margin

[jhonabreul]

Expected Behavior

We need lean to be able to model margin as crypto exchanges do. There is a difference between the used/available margin and the maintenance margin.

Binance and Bybit, for instance, the initial margin requirement is the position's used margin and it's deducted from the available margin. The maintenance margin is account wise and has nothing to do with the used/available margin.

This follows #9235

Actual Behavior

Lean uses the maintenance margin to calculate used and remaining margin, which is not accurate for crypto futures.

Potential Solution

Reproducing the Problem

System Information

Checklist

• I have completely filled out this template
• I have confirmed that this issue exists on the current master branch
• I have confirmed that this is not a duplicate issue by searching issues

• I have provided detailed steps to reproduce the issue

[jhonabreul]

Related #9241

[jhonabreul]

Closing in favor of #9241