feat: add AHeaderSubtitle component

[BogdanV3]

Please check if the PR fulfills these requirements

• [ ] The commit message follows semantic commit message guidelines
• [ ] The changes are documented in component docs and changelog
• [ ] The ESLint plugin has been updated if a new component is added
• [ ] Test have been added or modified, if appropriate
• [ ] Has been verified locally

What kind of change does this PR introduce?:

• feature

Closes #995

What is the current behavior?: https://github.com/cisco-sbg-ui/atomic-react/issues/20

What is the new behavior (if this is a feature change)?: https://github.com/cisco-sbg-ui/atomic-react/issues/995

Does this PR introduce a breaking change?: No

Other information:

[vercel[bot]]

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Name	Status	Preview	Updated
atomic-react	✅ Ready (Inspect)	Visit Preview	May 18, 2022 at 8:11PM (UTC)

[codecov[bot]]

Codecov Report

Merging #1215 (5c9286c) into master (f28534f) will decrease coverage by 0.01%. The diff coverage is 85.71%.

@@            Coverage Diff             @@
##           master    #1215      +/-   ##
==========================================
- Coverage   91.22%   91.20%   -0.02%     
==========================================
  Files         103      104       +1     
  Lines        3155     3162       +7     
  Branches     1053     1054       +1     
==========================================
+ Hits         2878     2884       +6     
- Misses        239      240       +1     
  Partials       38       38              

Impacted Files	Coverage Δ
framework/components/AHeader/AHeaderSubtitle.js	85.71% <85.71%> (ø)

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