Fix uninitialized Base::unique

[simPod]

What is the reason for this PR?

• A new feature
• Fixed an issue

Author's checklist

• Follow the Contribution Guide
• New features and changes are documented

Summary of changes

Base::unique property was not initialized in constructor and did not allow null. That may cause issues in classes accessing it while extending Base

Review checklist

• All checks have passed
• Changes are approved by maintainer

[pimjansen]

@GrahamCampbell guess we can accept this BC right after updating the definition?

[pimjansen]

Can we ensure that the BC check passes?

[simPod]

@pimjansen how? The null value was always there but it was typed as non-null so I think this is BC.

[pimjansen]

@pimjansen how? The null value was always there but it was typed as non-null so I think this is BC.

Ensure that the BC check allows it for now

[bram-pkg]

This looks fine to me.

[pimjansen]

@simPod will you update the PR accordingly the code guidelines? We need a green build to pass

[simPod]

@pimjansen how? The BC change is the point of this PR. $unique could always be null so it was a bug not to have it in type definition. Now the bug is fixed and it violates BC check, yes 🤔

[pimjansen]

@pimjansen how? The BC change is the point of this PR. $unique could always be null so it was a bug not to have it in type definition. Now the bug is fixed and it violates BC check, yes

In that case it will be a no fix since we are not running BC changes in our update policy for the current stream of Faker

[simPod]

Should I remove "Fix" from a title and target a version where this can be fixed?