feat: Add StudioFieldset component

[TomasEng]

Description

Added a StudioFieldset component based on Fieldset from The Design System.

Related Issue

• Implement new StudioCodelistEditor component #13342

Verification

• Your code builds clean without any errors or warnings
• Manual testing done (required)
• Relevant automated test added (if you find this hard, leave it and we'll help out)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.30%. Comparing base (a12dd61) to head (47b13e5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #13814   +/-   ##
=======================================
  Coverage   95.30%   95.30%           
=======================================
  Files        1650     1652    +2     
  Lines       21972    21978    +6     
  Branches     2583     2583           
=======================================
+ Hits        20940    20946    +6     
  Misses        787      787           
  Partials      245      245           

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[Konrad-Simso]

Nice work! 🚀