Maintaining Sort order when adding or editing contacts

[AbdulrahmanAlRammah]

Closes #175

[codecov]

Codecov Report

Attention: Patch coverage is 76.74419% with 10 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
.../java/seedu/address/commons/core/SortSettings.java	66.66%	7 Missing ⚠️
...rc/main/java/seedu/address/model/ModelManager.java	85.71%	2 Missing ⚠️
src/main/java/seedu/address/model/UserPrefs.java	87.50%	1 Missing ⚠️

Files with missing lines	Coverage Δ	Complexity Δ
...java/seedu/address/logic/commands/SeedCommand.java	100.00% <ø> (ø)	4.00 <0.00> (ø)
src/main/java/seedu/address/model/Model.java	100.00% <ø> (ø)	2.00 <0.00> (ø)
...a/seedu/address/model/person/PersonComparator.java	50.00% <ø> (ø)	5.00 <0.00> (ø)
src/main/java/seedu/address/model/UserPrefs.java	83.78% <87.50%> (+3.78%)	12.00 <2.00> (+2.00)
...rc/main/java/seedu/address/model/ModelManager.java	96.82% <85.71%> (-3.18%)	27.00 <3.00> (+3.00)	⬇️
.../java/seedu/address/commons/core/SortSettings.java	66.66% <66.66%> (ø)	5.00 <5.00> (?)

... and 6 files with indirect coverage changes

[liauzhanyi]

Just some naming issues to fix, otherwise I think great idea to make use of the preferences.json!

[liauzhanyi]

I think should be "Re-sorting"?

[liauzhanyi]

not sure if its just me but since "resort" is an actual word, it kind of requires at least a second read in order to understand what it meant. I think maybe sortPersonListAgain might be better? or if you prefer re-sort then reSortPersonList?

[liauzhanyi]

lgtm