Add restrictions to command inputs

[zhaojj2209]

Resolves #200.

Restricts user command inputs to one title/amount/date for adding transactions, one amount/date for finding transactions, and one amount for setting expense limit/saving goal.
Additional restrictions placed on find command such that the lower bound for amount/date should not be larger than the upper bound.

[codecov-io]

Codecov Report

Merging #201 into master will decrease coverage by 0.29%.
The diff coverage is 58.62%.

@@             Coverage Diff              @@
##             master     #201      +/-   ##
============================================
- Coverage     72.98%   72.68%   -0.30%     
- Complexity      824      835      +11     
============================================
  Files           134      134              
  Lines          2539     2596      +57     
  Branches        282      299      +17     
============================================
+ Hits           1853     1887      +34     
- Misses          580      597      +17     
- Partials        106      112       +6     

Impacted Files	Coverage Δ	Complexity Δ
...cs2103_w16_3/finesse/model/transaction/Amount.java	85.71% <ø> (ø)	11.00 <0.00> (ø)
...3_w16_3/finesse/model/transaction/Transaction.java	100.00% <ø> (ø)	10.00 <0.00> (ø)
..._w16_3/finesse/logic/parser/FindCommandParser.java	24.63% <27.27%> (+3.01%)	5.00 <1.00> (+1.00)
.../finesse/logic/parser/AddExpenseCommandParser.java	100.00% <100.00%> (ø)	7.00 <0.00> (+3.00)
...3/finesse/logic/parser/AddIncomeCommandParser.java	100.00% <100.00%> (ø)	7.00 <0.00> (+3.00)
...3_w16_3/finesse/logic/parser/ArgumentMultimap.java	100.00% <100.00%> (ø)	10.00 <2.00> (+2.00)
...er/budgetparsers/SetExpenseLimitCommandParser.java	100.00% <100.00%> (ø)	5.00 <0.00> (+1.00)
...ser/budgetparsers/SetSavingsGoalCommandParser.java	100.00% <100.00%> (ø)	5.00 <0.00> (+1.00)

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[yongping827]

LGTM

[zhaojj2209]

Future work:

• Add the same restrictions to the edit income/expense commands.
• Add input restrictions for bookmark income/expense commands.

[ianyong]

LGTM!

[yongping827]

LGTM