Suggestions for PnL Explain columns

[quantthingy]

Some small changes to make the PnL Explained report more inline with usual market practices in a multi asset environment:

Changes

• ScenarioPnl -> PnLExplained
• move Theta into the sum of Scenario PnL (oe PnL Explained) as Theta is part of the Taylor expansion, and is also model dependant
• HypotheticalCleanPnL -> CleanPnL (as Theta is now in PnL explained)

** New column ** PnLUnexplained = (CleanPnL - ExplainedPnL) this show the PnL part not explained by the greeks