Bind Events Subscription for manual event subscriber instance in AL.
Subscriber: Specifies how event subscriber functions in a Codeunit are bound to the Codeunit instance and the events that they subscribe to.
Manual Binding: For manual binding, Subscribers are bound to an event only if the BINDSUBSCRIPTION method is called from the code that raises the event.
BINDSUBSCRIPTION: Binds the event subscriber methods in the codeunit to the current codeunit instance for handling the events that they subscribe to.
This essentially activates the subscriber functions for the codeunit instance.