This performs the recommended setting updates from xcode, though I needed to turn off `ENABLE_USER_SCRIPT_SANDBOXING` as it does not seem to be fully compatible with flutter.
I also dealt with a warning of: "Extension declares a conformance of imported type 'String' to imported protocol 'Error'; this will not behave correctly if the owners of 'Swift' introduce this conformance in the future", by creating and using some custom error types.
Lastly, I fixed our podfile to ensure that the `IPHONEOS_DEPLOYMENT_TARGET` is at least 12, which is our project setting.
This fixes a few issues:
1) When updates are made, we will no longer create duplicate VPN profiles, rather we will update existing ones.
2) We will correctly update an existing profile when the site is running and an update is received, rather than attempting to create a new profile, which failed due to permissions errors.
3) We will always reload nebula, even if we can't successfully save the VPN profile.
4) The default polling interval of 15 minutes is restored (previously set to 30 seconds during testing).
So far in manual testing I've confirmed that I do not lose the tunnel to my lighthouse even after the original 30 minute expiration of a certificate. This confirms that reloads are occurring correctly. Additionally, duplicate sites are not created when updates occur while the site is disconnected.
