fix: #5100 Add viewbox to sankey

[sidharthv96]

📑 Summary

Adds viewbox attr to sankey diagram

Resolves #5100

You have to set the useMaxWidth option for it to scale down properly.

📏 Design Decisions

Describe the way your implementation works or what design decisions you made if applicable.

📋 Tasks

Make sure you

• 📖 have read the contribution guidelines
• 💻 have added necessary unit/e2e tests.
• 📓 have added documentation. Make sure MERMAID_RELEASE_VERSION is used for all new features.
• 🔖 targeted develop branch

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[codecov]

Codecov Report

Merging #5102 (160c7d3) into develop (f81e4d4) will decrease coverage by 1.24%.
Report is 4 commits behind head on develop.
The diff coverage is 100.00%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5102      +/-   ##
===========================================
- Coverage    79.41%   78.18%   -1.24%     
===========================================
  Files          166      166              
  Lines        13871    13874       +3     
  Branches       705      705              
===========================================
- Hits         11016    10847     -169     
- Misses        2703     2873     +170     
- Partials       152      154       +2     

Flag	Coverage Δ
e2e	83.68% <100.00%> (-1.56%)	⬇️
unit	43.04% <100.00%> (+0.01%)	⬆️

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

Files	Coverage Δ
...ages/mermaid/src/diagrams/sankey/sankeyRenderer.ts	74.19% <100.00%> (ø)
packages/mermaid/src/setupGraphViewbox.js	77.77% <100.00%> (+0.31%)	⬆️

... and 19 files with indirect coverage changes

[nirname]

Cool!