[QL] Handle Success or Failure of `application.open`

[jaxdesmarais]

Summary of changes

• Handle Success or Failure of application.open via invokedOpenURLSuccessfully
  • Add TODOs for future analytics PR
• Add new BTPayPalError.appSwitchFailed

Checklist

• ~[ ] Added a changelog entry~

Authors

• @jaxdesmarais

[scannillo]

Changes look good! But I think this needs 2 unit tests based on the bool result of application.open(redirectURL, options: [:])

[jaxdesmarais]

Changes look good! But I think this needs 2 unit tests based on the bool result of application.open(redirectURL, options: [:])

It looks like there is a test testTokenizeVaultAccount_whenPayPalAppApprovalURLPresent_attemptsAppSwitchWithParameters that is already asserting on this result. As far as testing the inverse, it looks like we always hardcode the result of application.open to success here so we don't actually have any tests around the failure case: https://github.com/braintree/braintree_ios/blob/4d4f107700b1483addeae0b3b7c741014f398a5d/UnitTests/BraintreeTestShared/FakeApplication.swift#L15

[scannillo]

As far as testing the inverse, it looks like we always hardcode the result of application.open to success here so we don't actually have any tests around the failure case:

Added a test for the failure case + error in this commit 4123bcf33938ee48c99af2d4805648c4178ff441