Validation Metrics & UI Updates

[s314cy]

List of changes

• list of UI updates
  • changed a few core component styles (e.g. IconCard, CustomButton, ButtonCard)
  • regrouped buttons that are related, with a describing title
  • aligned several remaining style mismatches
  • moved the navigation button components to their corresponding navigation bar component for more intuitive style and logic control
  • fixed the validation accuracy graph updates
• the validation panel
  • provides the full confusion matrix (for tasks with less than 8 classes)
  • provides sensitivity and f1-score for each label of binary classification tasks
  • provides the macro average f1-score for multiclass classification tasks

Related issues

• contributes to Validation metrics #367
• fixes label prediction for multi-class classification (replaced rounding by argmax)
• fixes the validation graph not being updated

[s314cy]

I'm limiting the scope of this PR to the UI changes forementioned, thus keeping the validation matrix for later (most of the code has been made "inactive" but kept) and merging this PR now

this is because:

• the PR is quite old
• some parts of develop overlapping with the code written here is broken; fixing develop before merging this would require more rebasing
• I'd like to focus my efforts on rebasing and merging Implementing end-to-end test with Byzantine-Robust Aggregator for cifar10 task #557 once develop is fixed, which would mean even more rebasing of this PR if it were to be merged after