[Technical] Marked the "not implemented" initializers as "unavailable" (closes #681)

[lennartstolz]

This PR addresses the issue described in #681 .

Description

When providing a custom initializer for subclasses of (mostly) UIKit
classes conforming to 'NSCoding' the required initializer must be
provided by those subclasses.

Most of them will never be used and stay with the auto suggestion
of Xcode causing a fatalError:

required init?(coder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

As this should never be called, I marked those initializers
with available(*, unavailable). Calling those initializers
will now fail at compile time instead of causing a
runtime crash.

Additionally, it will stop Xcode suggesting those initializers
as code completions.

[lennartstolz]

@inf2381 I may need your help here (And I saw that it also is a "frequent" issue of some contributors). Do you have any idea how to unblock the issue with circleci?
It says the test-an-scan pipeline is unauthorized.

(Unfortunately, I didn't work with circleci for ages)

AFAIK it's happening in this PR as well: #639

[inf2381]

Could you please login to CircleCI and grant access to your organization? If that solves the issue, I can update our contributing guidelines.

The issue is on our side, we'll come back to you later this day

[lennartstolz]

Thanks @inf2381 .
Yeah I tried everything on my side, even removed all private projects and organizations.
All of this didn't help. ;)

[inf2381]

Thanks @inf2381 .
Yeah I tried everything on my side, even removed all private projects and organizations.
All of this didn't help. ;)

The issue was that you didn't have access to the context on CircleCI where the access token for SonarCloud is stored. I deleted the context from config.yaml and stored an access key directly in the environment of CircleCI. It seems to be working now 🥳