E2e fixes

[ineiti]

This PR does the following:

• Comments and error handling
• Improve speed of docker build
• Add voting script to the backend
• Putting FormFromStore into a single place
• Correctly store and retrieve DKGs
• Synching of nonces is now done in dela
• Making tests pass

Thank you for opening a pull request with this project, please also:

Review hint

Each commit should be understandable on its own.

• add a brief description of your changes here
• assign the PR to yourself, or to the person(s) working on it
• start in draft mode and in progress pipeline in the project (if applicable)
• if applicable, add this PR to its related issue by one of the special keywords Closing keywords
• once it's ready
  • put it in the Review or Ready4Merge pipeline in the project (if applicable)
  • remove draft
  • assign a reviewer

[PascalinDe]

isn't that a different DELA repository now?

[ineiti]

go does some magic here:

$ go list -f '{{.Dir}}' go.dedis.ch/dela
.../packages/pkg/mod/github.com/c4dt/dela@v0.0.0-20240125143006-d9bfc5ad2f59

and because we kept the go.dedis.ch/dela as package name throughout the github.com/c4dt/d-voting, and rely on the replace directive in go.mod, I think it's OK.

Change my mind :)