Fix issue with generic class not rendering

[jgreywolf]

📑 Summary

Updated addClassesToNamespace function to split the classname/type to ensure correct item is being assigned to namespace

Resolves #4578

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[codecov]

Codecov Report

Merging #5098 (761fa27) into develop (f81e4d4) will decrease coverage by 2.30%.
The diff coverage is 66.66%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5098      +/-   ##
===========================================
- Coverage    79.41%   77.12%   -2.30%     
===========================================
  Files          166      166              
  Lines        13871    13873       +2     
  Branches       705      705              
===========================================
- Hits         11016    10699     -317     
- Misses        2703     3015     +312     
- Partials       152      159       +7     

Flag	Coverage Δ
e2e	82.38% <66.66%> (-2.86%)	⬇️
unit	43.03% <ø> (ø)

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

Files	Coverage Δ
packages/mermaid/src/diagrams/class/classDb.ts	82.47% <66.66%> (+8.51%)	⬆️

... and 22 files with indirect coverage changes

[sidharthv96]

Can you add some unit tests? Added.