Add duplicate checking for public address string in AddPA command

[chongtzezhao]

fixes #235 #226 #227 #222 #211 #247 #264

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 90.47619% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...ss/model/addresses/PublicAddressesComposition.java	71.42%	0 Missing and 2 partials :warning:

Files with missing lines	Coverage Δ	Complexity Δ
...ddress/logic/commands/AddPublicAddressCommand.java	89.74% <100.00%> (+5.12%)	9.00 <4.00> (+3.00)
...ss/logic/parser/AddPublicAddressCommandParser.java	88.00% <100.00%> (-0.47%)	4.00 <0.00> (ø)
...ss/model/addresses/PublicAddressesComposition.java	74.72% <71.42%> (-0.14%)	69.00 <2.00> (+2.00)	:arrow_down:

[chongtzezhao]

fixes break in retrievepa