Empty states for Overview page

[amsiglan]

Description

This PR makes following changes to the Overview page:

• Empty state for summary visualization and Alert/Finding stat
• Sorted recent alerts and findings in descending order

Issues Resolved

#464

Output screenshot

Check List

• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov-commenter]

Codecov Report

Merging #467 (a7f06a9) into main (ab6a342) will decrease coverage by 0.15%.
The diff coverage is n/a.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

@@            Coverage Diff             @@
##             main     #467      +/-   ##
==========================================
- Coverage   35.36%   35.21%   -0.15%     
==========================================
  Files         116      116              
  Lines        3133     3149      +16     
  Branches      492      501       +9     
==========================================
+ Hits         1108     1109       +1     
- Misses       1905     1920      +15     
  Partials      120      120              

Impacted Files	Coverage Δ
...ges/Overview/components/Widgets/TopRulesWidget.tsx	30.00% <0.00%> (-3.34%)	⬇️
...Overview/components/Widgets/RecentAlertsWidget.tsx	5.55% <0.00%> (-1.59%)	⬇️
...blic/pages/Overview/components/Widgets/Summary.tsx	2.85% <0.00%> (-0.48%)	⬇️
.../pages/Overview/components/Widgets/TableWidget.tsx	25.00% <0.00%> (ø)
...erview/components/Widgets/RecentFindingsWidget.tsx	0.00% <0.00%> (ø)
...es/Overview/components/Widgets/DetectorsWidget.tsx	5.26% <0.00%> (+5.26%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[opensearch-trigger-bot]

The backport to 2.5 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-2.5 2.5
# Navigate to the new working tree
cd .worktrees/backport-2.5
# Create a new branch
git switch --create backport/backport-467-to-2.5
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 a88c79176a33e9ee93aad718ca8d4a6f18b8f80a
# Push it to GitHub
git push --set-upstream origin backport/backport-467-to-2.5
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-2.5

Then, create a pull request where the base branch is 2.5 and the compare/head branch is backport/backport-467-to-2.5.