Feature/68 migration to null safety

[XavierPaquet-Rapold]

⁉️ Related Issue

Closes #68
Null safety

📖 Description

Migrate to null safety

🧪 How Has This Been Tested?

Everything was tested

☑️ Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Make sure to add either one of the following labels: version: Major,version: Minor or version: Patch.
• Make sure golden files changes were reviewed and approved.

[MysticFragilist]

LGTM! Good job Xavier, t'as bien fait ça, null safety nous voilà!!!😄 Merci à @apomalyn pour l'aide aussi!

[Udito3]

LGTM! Good job!!!! 😁

[MysticFragilist]

Autres que la question en haut LGTM! 😄

[github-actions]

This PR exceeds the recommended size of 1000 lines. Please make sure you are NOT addressing multiple issues with one PR. Note this PR might be rejected due to its size.

[github-actions]

Coverage after merging feature/68-migration-to-null-safety into master will be

78.13%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
lib
locator.dart	4.35%	100%	100%	4.35%	28, 30–42, 45–49, 52–54
lib/core/constants
preferences_flags.dart	0%	100%	100%	0%	61, 66, 68, 70–72, 75, 77–80, 82, 84
widget_helper.dart	100%	100%	100%	100%
quick_links.dart	100%	100%	100%	100%
emergency_procedures.dart	100%	100%	100%	100%
markers.dart	100%	100%	100%	100%
lib/core/managers
cache_manager.dart	0%	100%	100%	0%	30–31, 34–37, 40, 44, 46–49, 51, 59, 61–63, 65, 72, 74–77
course_repository.dart	97.30%	100%	100%	97.30%	249, 257, 259–260, 444–445
quick_link_repository.dart	85.71%	100%	100%	85.71%	39–40
settings_manager.dart	89.15%	100%	100%	89.15%	221, 227, 230, 234, 236, 256, 258–259, 272, 274–276, 39, 88
user_repository.dart	91.38%	100%	100%	91.38%	137–139, 188, 309–311, 95–97
lib/core/models
quick_link.dart	100%	100%	100%	100%
quick_link_data.dart	100%	100%	100%	100%
widget_models.dart	100%	100%	100%	100%
feedback_issue.dart	100%	100%	100%	100%
discovery.dart	100%	100%	100%	100%
group_discovery.dart	100%	100%	100%	100%
emergency_procedure.dart	100%	100%	100%	100%
faq_actions.dart	100%	100%	100%	100%
faq_questions.dart	100%	100%	100%	100%
lib/core/services
analytics_service.dart	0%	100%	100%	0%	13–14, 17, 20–22, 25, 30, 32–34, 38, 40–41, 43
app_widget_service.dart	80%	100%	100%	80%	71, 73–78
github_api.dart	0%	100%	100%	0%	100, 103, 108, 110–114, 116–117, 120, 128–131, 135–136, 138, 39, 42–43, 47, 51–55, 57–58, 60, 62, 64–65, 68, 76, 81–87, 91, 93, 95–97, 99
in_app_review_service.dart	0%	100%	100%	0%	16, 20, 23, 27
internal_info_service.dart	0%	100%	100%	0%	18–21, 24–29, 32, 34–38, 42–43
launch_url_service.dart	0%	100%	100%	0%	22–24, 27–29, 32–33, 35–36, 42, 60–61, 64
navigation_service.dart	0%	100%	100%	0%	27, 30–31, 33–34, 41–42, 45–46, 49–51, 53, 58, 61, 63–64, 67–69, 71–72
networking_service.dart	0%	100%	100%	0%	10–11, 13–15, 18–20
preferences_service.dart	69.09%	100%	100%	69.09%	119–120, 122, 36, 38, 40, 43–45, 69–70, 80–82, 85, 87–88
remote_config_service.dart	0%	100%	100%	0%	101–103, 106–108, 111–112, 114–117, 119, 124–126, 46–48, 51–53, 56–58, 61–63, 66–68, 71–73, 76–78, 81–83, 86–88, 91–93, 96–98
rive_animation_service.dart	0%	100%	100%	0%	12–13, 16, 19–20, 28, 32–33, 35
siren_flutter_service.dart	0%	100%	100%	0%	13–14, 18–19, 23–25, 29–31, 35, 41
lib/core/utils
cache_exception.dart	33.33%	100%	100%	33.33%	10, 12
animation_exception.dart	20%	100%	100%	20%	15, 17–19
utils.dart	70.83%	100%	100%	70.83%	12–15, 17–18, 50
login_mask.dart	5%	100%	100%	5%	12, 15–16, 18–20, 23–30, 33–34, 37–39
lib/core/viewmodels
grades_viewmodel.dart	100%	100%	100%	100%
grades_details_viewmodel.dart	96.55%	100%	100%	96.55%	53
choose_language_viewmodel.dart	100%	100%	100%	100%
quick_links_viewmodel.dart	100%	100%	100%	100%
faq_viewmodel.dart	41.67%	100%	100%	41.67%	30, 32–33, 35, 38, 41, 43
web_link_card_viewmodel.dart	62.50%	100%	100%	62.50%	35, 40–41
not_found_viewmodel.dart	100%	100%	100%	100%
profile_viewmodel.dart	96%	100%	100%	96%	126–127
dashboard_viewmodel.dart	81.11%	100%	100%	81.11%	146–148, 150, 153, 240–241, 255–260, 262, 271–272, 314, 354–355, 357, 377, 381, 418, 420, 425, 463, 479–481, 483, 488–489, 543, 548, 550, 552, 554, 556, 559–560, 562, 565, 567, 569–570, 572–573, 576–577, 589–590
startup_viewmodel.dart	92.50%	100%	100%	92.50%	103, 138–139
settings_viewmodel.dart	100%	100%	100%	100%
schedule_viewmodel.dart	80.77%	100%	100%	80.77%	100–105, 107, 122, 157–163, 202, 214, 269–270, 306, 356–360, 368–369, 392–395, 398–399, 431–432
login_viewmodel.dart	100%	100%	100%	100%
feedback_viewmodel.dart	97.14%	100%	100%	97.14%	63
schedule_settings_viewmodel.dart	77.38%	100%	100%	77.38%	120–124, 140, 142, 144, 147, 150–151, 153, 67, 69–74
more_viewmodel.dart	66%	100%	100%	66%	111–113, 115–116, 118, 123–124, 143–144, 146–147, 149–150, 153–154, 66
emergency_viewmodel.dart	7.69%	100%	100%	7.69%	18, 20, 22–23, 25–27, 31, 33–34, 41–42
security_viewmodel.dart	50%	100%	100%	50%	37–38, 42–44, 46, 51–52
lib/ui/utils
app_theme.dart	0%	100%	100%	0%	6, 72–74, 77–82, 86–88, 94–99
discovery_components.dart	93.23%	100%	100%	93.23%	103, 134, 165, 195, 225, 41, 459, 466–467, 469, 471–476, 72
loading.dart	100%	100%	100%	100%
lib/ui/views
login_view.dart	77.14%	100%	100%	77.14%	120–122, 152–153, 155, 168, 170, 172–174, 177, 183, 193, 209–210, 212, 257–258, 260–261, 58–60
grade_details_view.dart	95.78%	100%	100%	95.78%	142, 310, 66, 68–69, 74, 99
security_view.dart	75.41%	100%	100%	75.41%	108, 110–114, 45–47, 66–71
emergency_view.dart	54.55%	100%	100%	54.55%	34–40, 51–53
faq_view.dart	90.09%	100%	100%	90.09%	107–108, 203–207, 278–279, 282, 284
settings_view.dart	100%	100%	100%	100%
about_view.dart	71.64%	100%	100%	71.64%	129–130, 136–137, 143–144, 150–151, 157–158, 164–165, 170, 173, 175, 23–25, 92
more_view.dart	83.72%	100%	100%	83.72%	110–112, 161–162, 164, 204–205, 207,