Add a setting to retain IBAction for SPM.
Because IBAction and IBSegueAction defined under SPM were being falsely detected as unused, I added a configuration option to retain them.
https://github.com/peripheryapp/periphery/issues/212#issuecomment-2858120688
@ileitch In an SPM environment, due to the https://github.com/peripheryapp/periphery/issues/212#issuecomment-2858120688, the IBAction methods are being incorrectly detected as unused code, so if possible I’d really appreciate it if you could merge this PR — or would that be difficult?
Thanks for the contribution, however this behavior is a bug, and therefore we shouldn't introduce new options to workaround. I've requested an example project in https://github.com/peripheryapp/periphery/issues/212#issuecomment-3665965410 so that I can work on a fix.