EES-4930 Send Public API subscription notifications

[benoutram]

⚠️ The tests in this PR depend on the change to make Azurite available to the Publisher function integration tests made in #5099

This PR completes the work originally started by @jack-hive to send Public API subscription notifications, building on the work also added by @jack-hive in #5043, #5076 and #5056 which allowed subscribing and unsubscribing to Public API data sets.

In this PR a new queue triggered function ApiSubscriptionFunctions.NotifySubscribers is added to Notifier.

ApiSubscriptionFunctions.NotifySubscribers function

The function expects a ApiNotificationMessage queue message as input:

{
    "dataSetId" : "00000000-0000-0000-0000-000000000000",
    "dataSetFileId" : "00000000-0000-0000-0000-000000000000",
    "version" : "1.1"
}

On receipt of this message it will send email notifications using Gov.uk Notify for all verified subscribers of the data set.

It uses FluentValidation to throw a validation exception if any of dataSetId, dataSetFileId or version in the queue message are empty.

Notification email template

The email template is personalised with the data set title, version, a link to the data set file details page, and an unsubscribe link.
It expects values for these placeholders to be provided: data_set_title, data_set_url, data_set_version, unsubscribe_url.

Rename Notifier functions

I standardised the naming across all of Notifier's Publication and Public API subscription functions. The full list of functions is now:

PublicationSubscriptions_RequestPendingSubscription
PublicationSubscriptions_VerifySubscription
PublicationSubscriptions_Unsubscribe
PublicationSubscriptions_NotifySubscribers
PublicationSubscriptions_RemoveExpiredSubscriptions

PublicApiSubscriptions_RequestPendingSubscription
PublicApiSubscriptions_VerifySubscription
PublicApiSubscriptions_Unsubscribe
PublicApiSubscriptions_NotifySubscribers
PublicApiSubscriptions_RemoveExpiredSubscriptions

Changes to Publisher

The publisher functions have been changed to queue a ApiNotificationMessage message on publishing of data sets.

Full list of changes

This is a record of the changes I made to complete this work.

• Moved IApiSubscriptionTableStorageService/ApiSubscriptionTableStorageService from Notifier.Repositories to Notifier.Services.
• Moved Constants.NotifierTableStorageTableName and Constants.NotifierQueueStorage to outer scope.
• Formatted code and organised imports.
• Remove the unused IOptions<AppSettingsOptions> parameter from the ApiSubscriptionRepository constructor.
• Removed the unused FunctionContext parameter from the NotifySubscribers function.
• Added the ApiSubscriptionNotificationId environment property to appsettings.Local.json.example and the infrastructure ARM template.
• Renamed ApiSubscriptionStatus SubscriptionPending as Pending.
• Changed ApiNotificationMessage Version from type SemVersion to string to simplify serialisation.
• Added missing DataSetTitle to the fields returned in the NotifySubscribers table query, required for the email personalisation.
• Corrected the NotifySubscribers table query to exclude Pending subscribers from being sent notifications.
• Added validation of the ApiNotificationMessage to the NotifySubscribers function.
• Tidied up all Public API email template variables.
• Included DataSetFileId in ApiNotificationMessage and fixed the link to the data set file details page in the email.
• Corrected dataSetId for dataSetFileId in DataSetFileService.GetDataSetFile and dataSetFileService.ts to avoid ambiguity.
• Standardised function names across all Publication and Public API subscription functions.
• Added NotifySubscribersTests function integration tests.
• Made changes to all of the Gov.uk Notify Public API email templates consistent with the changes in this PR.
• Added new Key Vault secret ees-notifier-templateid-api-subscription-notification to all Azure environments (EES-5359).

[jack-hive]

I know it was me who named it like this, but I'm now thinking this might be better named as simply NotifierTableStorage.

And the fields inside could be renamed like:
PublicationPendingSubscriptionsTableName --> PublicationPendingSubscriptionsTable
...
...

[benoutram]

Ah yeah, good point, I think this does make things a little tidier. I've done this renaming now as a new commit. Thanks. 🙂