Closes https://github.com/CocoaPods/CocoaPods/issues/3689.

[Command] Ensure warnings are printed even when theres an exception

Deduplicate pod targets

Remove the "Pods-" prefix from the labels in the expected error messages, because the fixture targets are deduplicated.

For disambugiation with stdlib's debugging helper #inspect.

Instead of refering to the global configuration

One scoped target for each target definition

By iterating over the uniq pod targets, instead of all pod targets per aggregate target, where now the same PodTarget can occur multiple times.

s/target([ab])/target_\1/