compare trading performance

[mirthbottle]

comparing the gains of open positions with closed positions

so would this be for some timeframe, past 6 months ending in a month:

• open positions at that time (pull from gains for that date)
• positions closed during that timeframe (closed_positions for timeframe)

2 assets that then get compared
metrics:

• days held
• gain
• percent gain
• annualized percent gain

The 2 assets already exist, but need partition mappings

closed_positions computations include the transaction fees
but neither includes dividends transactions.
This needs to be added.