refactor: Dag screen to functional component

[tuliomir]

Acceptance Criteria

• The DAG screen should be refactored to functional component

Notes for reviewers

This screen relied heavily on local variables, instead of component state, to work. So the refactor had to change most of the data flow of this component. Many intermediate structures and helpers also had to be built, and this makes the diff almost unreadable.

I'd recommend looking at the file before and after to have a clearer understanding of the code changes.

Security Checklist

• Make sure you do not include new dependencies in the project unless strictly necessary and do not include dev-dependencies as production ones. More dependencies increase the possibility of one of them being hijacked and affecting us.