Add module storage

[yadunut]

WIP PR to add module storage. This works by

1. adding a new JsonModuleMapStorage which handles reading the JSON file from within the resources
   • The path is hardcoded and not parameterised as this file is not updatable.
   • This returns a ModuleMap, a mapping of ModuleCode to Module.
2. Separates the storage layer and the Model layer with JsonAdaptedModule and Module

Closes #32
Closes #23

[taufiq]

Holy cowabunga! This is a heavy PR 😮 Will get on it ASAP! 🤠

[codecov]

Codecov Report

Attention: Patch coverage is 37.17949% with 49 lines in your changes are missing coverage. Please review.

Project coverage is 72.80%. Comparing base (31eee46) to head (8f89cdd).

Files	Patch %	Lines
...va/seedu/address/storage/JsonModuleMapStorage.java	15.00%	17 Missing ⚠️
.../java/seedu/address/storage/JsonAdaptedModule.java	0.00%	14 Missing ⚠️
...in/java/seedu/address/model/module/ModuleCode.java	50.00%	7 Missing ⚠️
src/main/java/seedu/address/MainApp.java	0.00%	6 Missing ⚠️
...ain/java/seedu/address/storage/StorageManager.java	40.00%	3 Missing ⚠️
...ain/java/seedu/address/model/module/ModuleMap.java	66.66%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master      #35      +/-   ##
============================================
- Coverage     75.10%   72.80%   -2.31%     
- Complexity      430      432       +2     
============================================
  Files            76       78       +2     
  Lines          1386     1434      +48     
  Branches        128      129       +1     
============================================
+ Hits           1041     1044       +3     
- Misses          314      360      +46     
+ Partials         31       30       -1     

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[blaukc]

LGTM! Thanks for fixing my code LOL. Maybe taufiq can look thru first as well then merge since its good to read thru before doing his part i feel.

[yadunut]

Thanks for fixing my code LOL.

There isn't anything particularly wrong with the way you did, its how I would have done in almost any other project. In this project, they are very explicit with their separation between the Model and Storage, and thus, the code is extremely verbose as seen above. There are benefits to doing it like this, for example, when you'll be implementing the student <-> module integration. We can have completely different representations at the Model Layer as compared to the Storage Layer. Whereas if the JSON structures was embedded in the Model and Student, it would be very hard to separate the storage representation and the Model representation of our data.

[taufiq]

lgtm