Update DataNotification.md - added deletionType in delete event

Type of change

• Bug Fix
• Feature

Please provide link to gitlab issue or ADR(Architecture Decision Record)

Does this introduce a change in the core logic?

• [YES]

Does this introduce a change in the cloud provider implementation, if so which cloud?

• AWS
• Azure
• GCP
• IBM

Does this introduce a breaking change?

• [NO]

What is the current behavior?

In deletion event type event type we get "op" : "delete"

What is the new/expected behavior?

In deletion event type event type we will get additional attribute "deletionType" : "soft" or "deletionType" : "hard"

Have you added/updated Unit Tests and Integration Tests?

Yes

Any other useful information

ADR Link - home#93