Refactor code to use useReducer instead of useState. Fixes #7428
'file' and 'fileName' in the uploadParams were not set to null after
import. To avoid this change the code to set 'file' and 'fileName' to
null after importing is done.

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### Motivation and context
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fixes an open
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This change is required to make the code clear. The previous code uses
many `useState` to manage the state but this version uses `useReducer`
to manage all the states.
In the previous code `file` and `fileName` in the `uploadParams` were
not set to null after importing was done but this version set it to null
so it can not use the previous file while importing annotation.
it solves issue #7428

### How has this been tested?
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see how your change affects other areas of the code, etc. -->
The changes have been tested manually. The code was tested using
different sequences of annotation uploads. The state of each parameter
is tested by logging its state to the console.

### Checklist
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- [x] I submit my changes into the `develop` branch
- [x] I have created a changelog fragment <!-- see top comment in
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- ~~[ ] I have updated the documentation accordingly~~
- ~~[ ] I have added tests to cover my changes~~ 
- [x] I have linked related issues (see [GitHub docs](

https://help.github.com/en/github/managing-your-work-on-github/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword))
- ~~[ ] I have increased versions of npm packages if it is necessary~~

([cvat-canvas](https://github.com/opencv/cvat/tree/develop/cvat-canvas#versioning),

[cvat-core](https://github.com/opencv/cvat/tree/develop/cvat-core#versioning),

[cvat-data](https://github.com/opencv/cvat/tree/develop/cvat-data#versioning)
and

[cvat-ui](https://github.com/opencv/cvat/tree/develop/cvat-ui#versioning))

### License

- [x] I submit _my code changes_ under the same [MIT License](
https://github.com/opencv/cvat/blob/develop/LICENSE) that covers the
project.
  Feel free to contact the maintainers if that's a concern.

---------

Co-authored-by: Boris Sekachev <sekachev.bs@gmail.com>