refactor: removed unused default app

[Shahroz16]

As part of fall cleaning remove the unused default app from Flutter and replace it with a sample app that currently exists in a separate repo.

[github-actions]

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<type>: short description of change being made

If your pull request introduces breaking changes to the code, use this format:

<type>!: short description of breaking change

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feat: edit profile photo
refactor!: remove deprecated v1 endpoints
build: update npm dependencies
style: run formatter 

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