feat: Add remark command functionality

[SuhailLoya]

remark command allows user to add a small remark to person

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 27.69231% with 47 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...va/seedu/address/logic/commands/RemarkCommand.java	0.00%	24 Missing :warning:
...eedu/address/logic/parser/RemarkCommandParser.java	0.00%	9 Missing :warning:
.../java/seedu/address/model/util/SampleDataUtil.java	0.00%	6 Missing :warning:
...c/main/java/seedu/address/model/person/Remark.java	62.50%	1 Missing and 2 partials :warning:
.../java/seedu/address/storage/JsonAdaptedPerson.java	71.42%	1 Missing and 1 partial :warning:
.../seedu/address/logic/parser/AddressBookParser.java	0.00%	1 Missing :warning:
...c/main/java/seedu/address/model/person/Person.java	80.00%	0 Missing and 1 partial :warning:
src/main/java/seedu/address/ui/PersonCard.java	0.00%	1 Missing :warning:

Files with missing lines	Coverage Δ	Complexity Δ
...java/seedu/address/logic/commands/EditCommand.java	97.46% <100.00%> (+0.03%)	13.00 <0.00> (ø)
...a/seedu/address/logic/parser/AddCommandParser.java	100.00% <100.00%> (ø)	5.00 <0.00> (ø)
...ain/java/seedu/address/logic/parser/CliSyntax.java	85.71% <100.00%> (+2.38%)	1.00 <0.00> (ø)
.../seedu/address/logic/parser/AddressBookParser.java	90.47% <0.00%> (-9.53%)	12.00 <0.00> (ø)
...c/main/java/seedu/address/model/person/Person.java	95.00% <80.00%> (-2.23%)	20.00 <1.00> (+1.00)	:arrow_down:
src/main/java/seedu/address/ui/PersonCard.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
.../java/seedu/address/storage/JsonAdaptedPerson.java	95.91% <71.42%> (-4.09%)	11.00 <0.00> (ø)
...c/main/java/seedu/address/model/person/Remark.java	62.50% <62.50%> (ø)	4.00 <4.00> (?)
.../java/seedu/address/model/util/SampleDataUtil.java	20.00% <0.00%> (ø)	1.00 <0.00> (ø)
...eedu/address/logic/parser/RemarkCommandParser.java	0.00% <0.00%> (ø)	0.00 <0.00> (?)
... and 1 more