[PLAT-5127] Updated stub calculation method model to support overriden rates, effective dates for double ended stubs
[PLAT-4964] Added BOTH stub type
[PLAT-4964] Added support for generating schedules for double ended stub schedules
[PLAT-4964] Added support for generating schedules for double ended stub schedules
[PLAT-4964] Added support for generating schedules for double ended stub schedules
[PLAT-4964] Added support for generating schedules for double ended stub schedules
[PLAT-5696] Refactor of annuity builders