Update the style for severity

[AllForNothing]

1. Fixes tasks 1,2,4 of Update style for the UI #19249

Thank you for contributing to Harbor!

Comprehensive Summary of your change

Issue being fixed

Fixes #(issue)

Please indicate you've done the following:

• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
• Accepted the DCO. Commits without the DCO will delay acceptance.
• Made sure tests are passing and test coverage is added if needed.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed in website repository.

[codecov]

Codecov Report

Merging #19525 (3a9f714) into main (b337f51) will increase coverage by 0.03%.
The diff coverage is 53.33%.

@@            Coverage Diff             @@
##             main   #19525      +/-   ##
==========================================
+ Coverage   67.47%   67.51%   +0.03%     
==========================================
  Files         989      988       -1     
  Lines      108840   108777      -63     
  Branches     2752     2737      -15     
==========================================
- Hits        73445    73440       -5     
+ Misses      31433    31372      -61     
- Partials     3962     3965       +3     

Flag	Coverage Δ
unittests	67.51% <53.33%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...s/vulnerability-database/security-hub.interface.ts	82.35% <100.00%> (+4.57%)	⬆️
...ability-summary/vulnerability-summary.component.ts	66.66% <ø> (ø)
...ase/project/repository/artifact/artifact.module.ts	100.00% <ø> (ø)
...lt-tip-histogram/result-tip-histogram.component.ts	32.00% <ø> (ø)
...bility-database/single-bar/single-bar.component.ts	16.66% <12.50%> (+5.55%)	⬆️

... and 5 files with indirect coverage changes

[wy65701436]

lgtm