Add flow decider to v2

[AnuthaDev]

We need to add a function to payments_confirm_intent that will decide which flow to call (PereAuthenticate, Authenticate, PostAuthenticate, Authorize) based on parameters like Connector, payment method, authentication type etc.

This is a better abstraction compared to the current PreProcessing, CompleteAuthorize etc.

[Jatan196]

Hi, pl assign me above issue! I'm interested!!