STRATCONN-6441 - [Facebook CAPI] - Append Event functionality and refactor

[joe-ayoub-segment]

Adding appendvalue support for FB CAPI destination.
Also refactored to consolidate redundant code.

Testing

Unit tests updated.
Testing to be done in stage.

Security Review

Please ensure sensitive data is properly protected in your integration.

• Reviewed all field definitions for sensitive data (API keys, tokens, passwords, client secrets) and confirmed they use type: 'password'

New Destination Checklist

• Extracted all action API versions to verioning-info.ts file. example

[github-actions]

New required fields detected

Warning

Your PR adds new required fields to an existing destination. Adding new required settings/mappings for a destination already in production requires updating existing customer destination configuration. Ignore this warning if this PR is for a new destination with no active customers in production.

The following required fields were added in this PR:

• Destination: Facebook Conversions API (Actions), Action Field(s):append_event_details
• Destination: Facebook Conversions API (Actions), Action Field(s):append_event_details
• Destination: Facebook Conversions API (Actions), Action Field(s):append_event_details
• Destination: Facebook Conversions API (Actions), Action Field(s):append_event_details

Add these new fields as optional instead and assume default values in perform or performBatch block.

[codecov]

Codecov Report

❌ Patch coverage is 88.62974% with 39 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.49%. Comparing base (9c233ed) to head (c05e985).
⚠️ Report is 41 commits behind head on main.

Files with missing lines	Patch %	Lines
...destinations/facebook-conversions-api/functions.ts	84.64%	21 Missing and 18 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3556      +/-   ##
==========================================
+ Coverage   80.23%   80.49%   +0.26%     
==========================================
  Files        1270     1280      +10     
  Lines       23448    23577     +129     
  Branches     4688     4732      +44     
==========================================
+ Hits        18813    18978     +165     
+ Misses       3764     3720      -44     
- Partials      871      879       +8     

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