Revamp reallocations to use Budget Events and Budget Line Items tables for better tracking instead of a text field.

[kcbimonte]

• Change Reallocations table structure to reallocation -> legacy and current
• Current should have the following fields (R_ID, From_BLI, To_Existing?, Existing_BLI, New Descript, Transfer_Amount, Notes, Timestamp)
• Migrate Legacy to the new structure if possible