Fixed an issue where multiple persistent iframes were created for id syncs and segment destinations

[carterworks]

Description

When firing off a referrer-hideable image for destinations and ID syncs, if there is not an iframe in memory, look in the document for one before creating a new one.

Related Issue

PDCL-8050 comment from Ian Ramsey.

Version 2.10.0 and PR #848 was supposed to restrict the Web SDK from creating one iframe per ID sync/segment destination, but the customer deployed it to their beta site (connect from a UK VPN location) and the issue was still there–many iframe[name="Adobe Alloy"] elements appeared.

Motivation and Context

I am at a loss for why #848 did not solve the issue, but here we are.

Screenshots (if appropriate):

Screenshot of persistent issue on 2.10.0

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (non-breaking change which does not add functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA or I'm an Adobe employee.
• I have made any necessary test changes and all tests pass.
• I have run the Sandbox successfully.