Issues with PRODUCT_BUNDLE_IDENTIFIER handling in iOS projects #86

I'm experiencing several issues with the package_rename package when renaming iOS projects, specifically related to the PRODUCT_BUNDLE_IDENTIFIER even with " for extensions.

Observed Issues

1. After running dart run package_rename, the PRODUCT_BUNDLE_IDENTIFIER for extensions (e.g., ImageNotification) does not correctly include the extension part after the dot, whereas RunnerTests is handled properly. Even when double quotes are used around the PRODUCT_BUNDLE_IDENTIFIER, the extension part is ignored for some cases.
2. Unlike Android, which has an override_old_package option, there is no straightforward way to override the old package name in iOS projects.
3. Xcode's known behavior of removing double quotes from PRODUCT_BUNDLE_IDENTIFIER in the project.pbxproj file when saving the project (either through the UI or via CLI commands) further complicates the process. This often requires manual correction and can break automation scripts that rely on the correct formatting.

Expected Behavior

• The package_rename package should correctly update the PRODUCT_BUNDLE_IDENTIFIER for all extensions, ensuring the extension part after the dot is preserved, regardless of whether double quotes are used.
• An option similar to override_old_package for Android should be provided for iOS to easily override the old package name.

Implementing these improvements would significantly enhance the usability and reliability of the package_rename package for iOS projects.