fix: move filenameUtils from shared to studio-pure-functions

[standeren]

Description

Move filenameUtils from shared to studio-pure-functions in order to use a file name util function in the content library.

Related Issue(s)

• Editing code list ID's in the content library #13951

Verification

• Your code builds clean without any errors or warnings
• 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 95.32%. Comparing base (6a1351e) to head (d9d6ec0).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #14134   +/-   ##
=======================================
  Coverage   95.31%   95.32%           
=======================================
  Files        1779     1780    +1     
  Lines       23156    23160    +4     
  Branches     2689     2689           
=======================================
+ Hits        22072    22078    +6     
  Misses        835      835           
+ Partials      249      247    -2     

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