Add recurrence ability for income and spending

Will create Junit test in another PR please check soundness of this implementation. At each startup, each spending and income list will be iterated and checked if they are a recurring event through parser(similar to command, return the recurrence type class to the abstract recurrence class). The class then calls its method according to income or spending type and updates the list.

Currently, users are unable to set recurring expenses and income, thus to increase their efficiency, there will be a optional parameter between 2 '~' to indicate daily, monthly or year recurrences in the entry. List will be updated and sorted upon re-login in the future.

AY2425S1-CS2113-W14-1 / tp

Add recurrence ability for income and spending #65