Migrate to null safety

[aman-singh7]

Fixes #99

Describe the changes you have made in this PR -

Screenshots of the changes (If any) -

Note: Please check Allow edits from maintainers. if you would like us to assist in the PR.

[manjotsidhu]

@aman-singh7 in CI/CD build step you can remove --no-sound-null-safety

https://github.com/CircuitVerse/mobile-app/blob/master/.github/workflows/ci.yml#L31

[aman-singh7]

@manjotsidhu migration is done. I am currently refactoring the test. Could you test the app when available and do let me know any issues?

[manjotsidhu]

@aman-singh7 the changes are working fine. Will review the code soon.

[aman-singh7]

@manjotsidhu The CI is failing due to the IOS build. Can you update the Podfile as I don't have Mac?

[manjotsidhu]

@aman-singh7 I will update the pods soon

[coveralls]

Pull Request Test Coverage Report for Build 1696831596

• 448 of 617 (72.61%) changed or added relevant lines in 104 files are covered.
• 31 unchanged lines in 12 files lost coverage.
• Overall coverage decreased (-0.4%) to 71.894%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lib/cv_theme.dart	1	2	50.0%
lib/services/API/ib_api.dart	2	3	66.67%
lib/ui/components/cv_add_icon_button.dart	0	1	0.0%
lib/ui/components/cv_flat_button.dart	0	1	0.0%
lib/ui/views/base_view.dart	1	2	50.0%
lib/ui/views/groups/my_groups_view.dart	4	5	80.0%
lib/ui/views/groups/update_assignment_view.dart	8	9	88.89%
lib/ui/views/ib/builders/ib_pop_quiz_builder.dart	1	2	50.0%
lib/ui/views/ib/builders/ib_subscript_builder.dart	0	1	0.0%
lib/ui/views/ib/builders/ib_superscript_builder.dart	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
lib/models/dialog_models.dart	1	50.0%
lib/services/dialog_service.dart	1	0%
lib/ui/views/contributors/components/contributors_donate_card.dart	1	84.21%
lib/ui/views/contributors/components/contributors_support_card.dart	1	94.44%
lib/ui/views/home/components/feature_card.dart	1	93.33%
lib/ui/views/ib/ib_landing_view.dart	1	66.67%
lib/ui/views/ib/ib_page_view.dart	1	58.77%
lib/ui/views/teachers/components/teachers_card.dart	1	94.74%
lib/models/assignments.dart	2	95.45%
lib/ui/views/ib/components/ib_pop_quiz_button.dart	2	0%

Totals
Change from base Build 1645684340:	-0.4%
Covered Lines:	3860
Relevant Lines:	5369

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💛 - Coveralls

[manjotsidhu]

[Nitish145]

Thanks @aman-singh7 for your valuable contributions here.