MWPW-206423: Apply promos to prices inside custom fields

[Axelcureno]

customFields arrives as an array, not a string, so scanMasElements skipped it and promos never reached custom-field prices.

Resolves https://jira.corp.adobe.com/browse/MWPW-206423
QA Checklist: https://wiki.corp.adobe.com/display/adobedotcom/M@S+Engineering+QA+Use+Cases

• C1. Cover code with Unit Tests
• C2. Add a Nala test (double check with #fishbags if nala test is needed)
• C3. Verify all Checks are green (unit tests, nala tests)
• C4. PR description contains working Test Page link where the feature can be tested
• C5: you are ready to do a demo from Test Page in PR
• C.6 read your Jira one more time to validate that you've addressed all AC's and nothing is missing

Test URLs:

• Before: https://www.stage.adobe.com/creativecloud/business.html?country=my
• After: https://www.stage.adobe.com/creativecloud/business.html?country=my&mas-io-url=https://14257-merchatscale-axel.adobeioruntime.net/api/v1/web/MerchAtScale

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Commits

• da9598d ✅ (latest)
• 8c72bf6 ✅
• 2ae9b9d ✅
• 7310c05 ✅
• a416b11 ✅
• d37a799 ✅
• 29569b5 ✅
• 1060dbe ✅

[github-actions]

SNOW Change Request Transaction ID [IO]: 0000019c1eec85a3-20c52b14

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.76%. Comparing base (d06ea2e) to head (da9598d).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1208      +/-   ##
==========================================
- Coverage   90.81%   90.76%   -0.05%     
==========================================
  Files         319      319              
  Lines      101857   101857              
==========================================
- Hits        92498    92450      -48     
- Misses       9359     9407      +48     

see 11 files with indirect coverage changes

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[yesil]

not sure why a new swc build is needed. If swc must be changed, I would expect also package-lock.json to be in the PR.

[afmicka]

@Axelcureno had something overwritten your IO namespace for this PR? I don't see the fix

Will see later if i merge something else but given your automatic branch updates, we will need to coordinate validation of your PRs with IO changes.