Remove native iOS tests

[okwasniewski]

Summary:

This PR removes native iOS tests as they are no longer used.

Unfortunately, this change creates a big diff in HelloWorld.xcodeproj/project.pbxproj We should annotate it in upgrade helper. But less code to maintain for users is always better 👍🏻

Manual Instruction for upgrade helper

1. Open the xcworkspace
2. Remove the target
3. Open the Podfile
4. Remove the section for the Tests
5. rerun pod install.

Changelog:

[IOS] [REMOVED] - Native iOS tests

Test Plan:

1. Create a new project
2. Test if there is no sign of native tests in Xcode
3. Build the app

[thymikee]

Can you add manual instructions of what needs to be changed in Xcode, so that it stays in this PR and can be easily referenced / copied over to the Upgrade Helper?

[okwasniewski]

@thymikee I've added additional instructions for manual steps in Xcode if users don't want to deal with editing the file manually

[cipolleschi]

Instructions could be simpler: it should be enough to:

1. Open the xcworkspace
2. Remove the target
3. Open the Podfile
4. Remove the section for the Tests
5. rerun pod install.

Step 5 should take care of all the other parts.

[okwasniewski]

Thanks @cipolleschi, I upgraded the instructions