Refactor repositories to remove unecessary Future

[apomalyn]

📖 Description

Refactor the existing repositories to remove unnecessaries Future. Also, add tests to the modified repositories.

⁉️ Related Issues

• N/A

🖼️ Screenshots:

❌

🧪 How to test the change?

1. Open and use the application as normal

☑️ Checklist before requesting a review

• [x] I have performed a self-review of my code.
• [x] I have added/updated tests.
• [x] Make sure to add either one of the following labels: version: Major,version: Minor or version: Patch.

[github-actions[bot]]

Coverage after merging feat/100-repos into feat/100 will be

44.36%

Coverage Report for Changed Files

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
lib/src/core/repositories
kana_repository.dart	100%	100%	100%	100%
kanji_repository.dart	100%	100%	100%	100%
vocabulary_repository.dart	100%	100%	100%	100%
lib/src/core/services
kana_service.dart	0%	100%	100%	0%	10–12, 15, 17–18, 21, 25–26, 29–30, 32, 35–36, 39–40
kanji_service.dart	0%	100%	100%	0%	10, 9
vocabulary_service.dart	0%	100%	100%	0%	10, 9
lib/src/quiz
quiz_view_model.dart	0%	100%	100%	0%	22, 26, 28–29, 31, 33, 35, 37–40, 43–44, 47–49, 52–53, 55–57, 60, 65–67, 69–70

[github-actions[bot]]

Bump version from 0.14.0+1 to 0.14.1+1

[github-actions[bot]]

Coverage after merging feat/100-repos into main will be

46.90%

Coverage Report for Changed Files

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
lib/src/core/repositories
kana_repository.dart	39.62%	100%	100%	39.62%	42–45, 47–51, 54–60, 70–73, 75–79, 82–88
kanji_repository.dart	31.82%	100%	100%	31.82%	26–30, 32, 35–40, 42–43, 45
vocabulary_repository.dart	35%	100%	100%	35%	26–31, 33, 36–41
lib/src/core/services
kana_service.dart	0%	100%	100%	0%	10–12, 15, 17–18, 21, 25–26, 29–30, 32, 35–36, 39–40
kanji_service.dart	0%	100%	100%	0%	10, 9
vocabulary_service.dart	0%	100%	100%	0%	10, 9
lib/src/quiz
quiz_view_model.dart	0%	100%	100%	0%	22, 26, 28–29, 31, 33, 35, 37–40, 43–44, 47–49, 52–53, 55–57, 60, 65–67, 69–70