This reverts commit 86c7635b45, reversing
changes made to c77f2b92df.
Some real world cases hit errors with this change, due to the new offset
logic attempting to create Adjustments with invalid parameters.
Will identify exact conditions that cause this error and add as a test
case before remerging.
Instead of `HistoryLoader` containing separate adjustment calculation
logic, use `SQLiteAdjustmentReader.load_adjustments`.
This change required the addition of two offset parameters to
`load_adjustments` since the perspective on the data from within
`schedule_function` is skewed from how Pipeline looks at historical
data.
This is working towards creating an `AdjustmentReader` abc which
`SQLiteAdjustmentReader` and a upcoming continuous future adjustment
reader will share.