Migrate the app to Null Safety

[pawan2806]

Feature request :

I want to migrate the app to null safety.

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Describe the solution you'd like :

https://dart.dev/null-safety/migration-guide

Describe alternatives you've considered :

A clear and concise description of any alternative solutions or features you've considered.

Describe how this feature will be useful to our readers :

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Additional context :

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[0xapurv]

Hey @pawan2806 Can I work on this issue, I'm a Gssoc'21 participant too.

[ayushvrma]

Hey can you grant me this issue?

[Priyanshu078]

Please assign me this issue
I can solve this issue

[pratyushmp]

Okay @Priyanshu078, the issue is assigned to you!

[Priyanshu078]

@pratyushmp 2 dependencies don't have their null safety version.
modal_progress_hud,
awesome_slider
So what to do now

[pratyushmp]

@Priyanshu078 If you can search for some alternatives to these packages having the same functionality that would be good