[CHNL-13246] add webview popup chrome

[ab1470]

Description

This adds the "chrome" around the WebView that will be used for the IAM content. The new KlaviyoWebWrapperViewController wraps the KlaviyoWebViewController and adds an inset, drop shadow, background blur, and/or background tint. These styles can all be customized using the KlaviyoWebWrapperStyle struct.

This PR addresses CHNL-13246.

Check List

• Are you changing anything with the public API?
• Have you tested this change on real device?
• Are your changes backwards compatible with previous SDK Versions?
• Have you added unit test coverage for your changes?
• Have you verified that your changes are compatible with all the operating system version this SDK currently supports?

Manual Test Plan

Run the Xcode Preview within the KlaviyoWebWrapperViewController file and validate that the view looks and works as expected.

Supporting Materials

Here are some examples of what the KlaviyoWebWrapperViewController looks like with different styles applied:

Blurred background	Tinted background

[ab1470]

Closing this as we've decided on a different approach for MVP. We can revisit this PR, if necessary, at a future date.