NoSQL

[thePeras]

Closes #1391 closes #755

Used Object Box, which is not the ideal approach since it require new annotations on models and don't rely on the existing serialization.

Bus stops remain in sqlite since they are not working and fix code need to be written.

Comparing SQlite and NoSQL

I run a simple experiment to compare the read and initialization times with my personal Exams data (around total 8 exams)

• The read values are the mean of 5 experiments with the DB already up.
• The DB initialization values result from 3 experiments, no schema migrations involved.

---	DB initialization	Reads
SQLite	19ms	15ms
ObjectBox (NoSQL)	161ms	2ms

Note: The NoSQL db initilization already opens the file used for all models where the SQLite only opens the Exams database

Conclusion

Since we had 9 databases and assuming they all boot up the same time as Exams, sequentially all of them would make 171ms to set up. Base on that, both of the technologies have similar db initialization times for a scenario using all the models (example: homepage with all of possible cards). However, read times were significantly decreased.

[thePeras]

As discussed in meeting:

• Close and use isar, remove library ocupation database and move Profile to PreferencesController temporary.

• Some things of PreferencesController should migrate to database, and Preferences is for Preferences, no more than that.

• Implement in just one file, database

[thePeras]

Currently with two files implementation.
Next Step: Join everything in a single singleton class called Database. ✅

[thePeras]

Configured the Database Interface and added instructions to view it in the readme.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 132 lines in your changes missing coverage. Please review.

Project coverage is 12%. Comparing base (b784754) to head (03ddb21).
Report is 2 commits behind head on develop.

Additional details and impacted files

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##           develop   #1411    +/-   ##
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+ Coverage       12%     12%    +1%     
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  Files          265     258     -7     
  Lines         7382    7189   -193     
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  Hits           819     819            
+ Misses        6563    6370   -193