feat: Added new icons and added composition example to styleguide

[dsmmcken]

Added dhOrganizationAdd icon for ACL editor and dhAddSmall for composition if needed somewhere else. Also added composition example to styleguide.

[codecov]

Codecov Report

Merging #1294 (0db68bc) into main (29ed459) will decrease coverage by 0.01%.
The diff coverage is 14.28%.

@@            Coverage Diff             @@
##             main    #1294      +/-   ##
==========================================
- Coverage   45.49%   45.48%   -0.01%     
==========================================
  Files         504      504              
  Lines       34826    34833       +7     
  Branches     8688     8688              
==========================================
+ Hits        15844    15845       +1     
- Misses      18931    18937       +6     
  Partials       51       51              

Flag	Coverage Δ
unit	45.48% <14.28%> (-0.01%)	⬇️

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Impacted Files	Coverage Δ
packages/code-studio/src/styleguide/Icons.tsx	55.17% <14.28%> (-5.62%)	⬇️

[bmingles]

Changes look good to me.

I did notice that our icon search seems to expect a dash cased string instead of camelCase. I don't think this is related to this change at all, so approving.