Allow cost parameter for deliveries to take in optional cents input

[kaajinn]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 60.00000% with 4 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...c/main/java/seedu/address/model/delivery/Cost.java	75.00%	2 Missing ⚠️
...odel/delivery/exceptions/InvalidCostException.java	0.00%	2 Missing ⚠️

Files with missing lines	Coverage Δ	Complexity Δ
...java/seedu/address/logic/commands/SortCommand.java	55.55% <ø> (ø)	10.00 <0.00> (ø)
...delivery/exceptions/DeliveryNotFoundException.java	0.00% <ø> (ø)	0.00 <0.00> (ø)
...c/main/java/seedu/address/model/delivery/Cost.java	85.71% <75.00%> (-14.29%)	4.00 <1.00> (ø)
...odel/delivery/exceptions/InvalidCostException.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)