Fix popover padding

[Harjun751]

What is the purpose of this pull request?

• Documentation update
• Bug fix
• Feature addition or enhancement
• Code maintenance
• DevOps
• Improve developer experience
• Others, please explain:

Resolves #2896

Overview of changes:
Fixes missing popover padding

Anything you'd like to highlight/discuss:
This issue resulted from the Bootstrap v5.3 upgrade. It seems that Bootstrap extracted some values into scoped variables - for the popover, they'd only apply on elements with the .popover class. So adding this class to the popover element fixes the problem.

There were some slight issues with the dark theme style, like this white padding here:

So I just overrid some of the styles. Let me know if this looks okay.

Testing instructions:

Proposed commit message: (wrap lines at 72 characters)

Fix popover padding

---

Checklist: ☑️

• Updated the documentation for feature additions and enhancements
• Added tests for bug fixes or features
• Linked all related issues
• No unrelated changes

---

Reviewer checklist:

Indicate the SEMVER impact of the PR:

• Major (when you make incompatible API changes)
• Minor (when you add functionality in a backward compatible manner)
• Patch (when you make backward compatible bug fixes)

At the end of the review, please label the PR with the appropriate label: r.Major, r.Minor, r.Patch.

Breaking change release note preparation (if applicable):

• To be included in the release note for any feature that is made obsolete/breaking

Give a brief explanation note about:

• what was the old feature that was made obsolete
• any replacement feature (if any), and
• how the author should modify his website to migrate from the old feature to the replacement feature (if possible).

[Harjun751]

Happy holidays btw heehee

[codecov]

Codecov Report

❌ Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 71.32%. Comparing base (79c1860) to head (fc1ec1c).

Files with missing lines	Patch %	Lines
packages/vue-components/src/Popover.vue	85.71%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2900   +/-   ##
=======================================
  Coverage   71.32%   71.32%           
=======================================
  Files         133      133           
  Lines        7232     7232           
  Branches     1714     1705    -9     
=======================================
  Hits         5158     5158           
  Misses       1973     1973           
  Partials      101      101           

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[damithc]

Thanks for tackling this, @Harjun751 👍

[gerteck]

LGTM! Nice touch for the dark mode! Nice and clean solution ~

happy holidays!