Create settings infrastructure for Consent Mode

[aaemnnosttv]

Feature Description

Support for Consent Mode will introduce new settings on the settings screen. This issue is just about adding the main Setting infrastructure which is common for all settings.

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Do not alter or remove anything below. The following sections will be managed by moderators only.

Acceptance criteria

• Settings for Consent Mode should be added on the server side.
• The shape of the settings should be be modelled as follows:

  'enabled' => boolean
  'regions' => array<ISO 3166-2 coded string>

• The default value for enabled should be false.
• The default value for regions should be the list of EEA country codes.

Implementation Brief

• Follow the Consent_Mode_Settings class from the branch hack/como.
• Include the Consent_Mode class from the above branch, but only include the parts which bootstrap the settings.
• If the consentMode feature flag is enabled, register an instance of the Consent_Mode class in Plugin.

Test Coverage

• Provide PHPUnit test coverage for the above changes.

QA Brief

• No QA needed, test coverage can be verified during CR.

Changelog entry

• Add settings model for Consent Mode.

[aaemnnosttv]

IB ✅