[WIP] Automated iOS Build

[jeroenpg]

Description

This PR solves #100. Once this merged we will have a new workflow (iOS) which uploads a self signed IPA that can be installed on simulators only (and jailbroken iOS devices). Once ITO has established itself as legal entity, and is enrolled in the apple developer program we can update this workflow to support installing on real iOS devices.

This PR uses the https://github.com/ito-org/ios-certificates repository as storage location for encrypted provisioning profiles and code signing identity as described in https://codesigning.guide. The certificates present there expire on 20th April 2030 23:10:30 CEST.

To do's

• [ ] Await discussion in #146
• [ ] react-native-ito currently fails to build, needs https://github.com/ito-org/react-native-ito/pull/26 to be merged before we can continue
• [ ] Needs to have a secret added to this repository by an admin