[FEATURE] payment flow for DDC

### Feature Description

There are couple of different payment related endpoints which can map to a payment operation which finally maps to a connector action. As of today, `/redirect/complete/{connector}` is being used for multiple different use cases in different connectors:
1. DDC collection
2. 3DS auth completion

This endpoint maps to CompleteAuthorize operation which maps to CompleteAuthorize connector action, and connector integration in HS decides which relevant step should be executed next based on the current payment status.

Aim is to define a separate endpoint <> payment operation <> connector action for DDC flows.

### Possible Implementation

TBA

### Have you spent some time checking if this feature request has been raised before?

- [x] I checked and didn't find a similar issue

### Have you read the Contributing Guidelines?

- [x] I have read the [Contributing Guidelines](https://github.com/juspay/hyperswitch/blob/main/docs/CONTRIBUTING.md)

### Are you willing to submit a PR?

None

Start by tracing the `/redirect/complete/{connector}` endpoint, the CompleteAuthorize operation, and the CompleteAuthorize connector action described in the issue. Define what separate endpoint, payment operation, and connector action are needed for DDC collection, then verify that the existing 3DS auth completion flow remains distinct; the implementation is currently marked TBA.

Written by the indexing model from the issue text.