[backend] fix entityType for external ref indexing (#11154)

[CelineSebe]

Proposed changes

• add entityType and parentTypes in elastic object for the file indexing

Related issues

• closes Users outside main org can’t see external reference files in global search #11154

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case (coverage and e2e)
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.52%. Comparing base (f8602cc) to head (0b3d0b5).
⚠️ Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
...atform/opencti-graphql/src/database/file-search.js	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #12811      +/-   ##
==========================================
- Coverage   66.53%   66.52%   -0.01%     
==========================================
  Files         752      752              
  Lines       79746    79749       +3     
  Branches     8556     8557       +1     
==========================================
+ Hits        53056    53057       +1     
- Misses      26690    26692       +2     

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