FEAT: Add "on delete" hook to integration

Description

As a user, I might want an integration to clean up data that it created. This might include cleaning up integration specific settings on the 3rd party platform. Users would have the ability to specify if this should be done - we dont want to do this by default. This should be doable from the platform and the CLI.

Solution

API:

• Add a abstract destroy(eventId: Event['id']) function to base.integration.ts
• Write implementation of this function across the various integrations
• Accept an optional query parameter cleanUp in DELETE /api/integration/:slug endpoint
• Update the service layer to call integrationObject.destroy() if cleanUp is set to true
• Delete KS_PRIVATE_KEY from the hosted app if its a platform integration (eg: Vercel)
• Send a notification to the channels if it is a communication integration (eg: Discord, Slack)

CLI:

• We should be able to issue a command like keyshade integration delete <slug> --clean-up that will delete the integration data.

Platform:

• There should be a checkbox in Delete Integration dialog that allows us to do this.

Packages:

• @ keyshade/schema should have a cleanUp field added in DeleteIntegrationRequestSchema
• @ keyshade/api-client should pass the cleanUp field as a query parameter

Additional Context

The details in this issue provides a basic guideline that you can follow to implement the functionality. This is by no means the final implementation - if you have suggestions, please feel free to drop them below.

<!-- upstream-issue: keyshade-xyz/keyshade#1003 -->