Soft delete recipient lists and notification configs.

[lache-melvin]

Describe the bug

Given there is a many-many join table for the relationships between notification configs and their recipients/recipients lists, you currently get a foreign key constraint violation if you try to delete a notification config while has recipients, or a recipient list while it is associated with a notification config.

Recipients have soft deleted implemented on them, we also need it on RecipientLists and NotificationConfigs.

To Reproduce

Steps to reproduce the behaviour:

Add a recipient list to a notification config.

• Try to delete the notification config (see error)
• Try to delete the recipient list (see error)

Expected behaviour

No errors, delete (softly) the entities

Additional context