Auth Tab, Close listener functionality

[kgangineni]

Summary of changes

• Introduces auth tab functionality
• introduces new overloaded function
  kotlinfun start( activity: Activity, request: PayPalWebCheckoutRequest, activityResultLauncher: ActivityResultLauncher<Intent>, callback: PayPalWebStartCallback ) { }
  to pass activityResultLauncher parameter
• Auth tab is allowed on devices with chrome version 137+ (may be hard to create in emulator but able to do in pixel devices)
• API works including callback in ActivityLauncher on all chrome versions, it might not have additional security provided auth tab in lower versions of chrome

Checklist

• Added a changelog entry

Authors

List GitHub usernames for everyone who contributed to this pull request.