DPP-4090 Add COPPA support to iOS Publisher SDK

[csminticiuc]

Changes:

• Updated CHANGELOG.md.
• Added property childDirectedTreatment to Criteo singleton.
• The property childDirectedTreatment is actually stored in the BidManager class, not Criteo class.
• The property childDirectedTreatment is then passed from BidManager to CR_ApiHandler and then to CR_BidRequestSerializer and translated into regs.coppa in the body request parameters.
• Updated keys from CR_ApiQueryKeys to not be optional when used in Swift.
• Added UI toggles for setting the childDirectedTreatment property in the CriteoAdViewer project application.
• Added and Updated corresponding tests in the modified classes.

Jira ticket: DPP-4090

Before	After

[TurpIF]

A general note on commit structure. I see that you're applying the fixup strategy in your PR. I would recommend you to rather rebase so that the commit history stay cleaned. I see that it is not explicitly written in the iOS repository, although it is implicitly in the Android one: https://github.com/criteo/android-publisher-sdk/blob/main/CONTRIBUTING.md#pull-requests

Generally, we target that each commit should:

• be concise and small to ease the review
• have a meaningful explaining the why of the commit
• be correct from the CI point of view (in GH flow, it is quite difficult to check this, but please try)
• be correct from a reviewer point of view (ie: amending rather than fixing)
• be readable
• is tested accordingly: no tests means that you'll have to replace the CI and execute the test manually for every PR/release

As a side effect, applying such rules is helping when reverting.