refactor(payments): Add platform merchant account checks for payment intent

[ThisIsMani]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

Description

Currently payment_intent stores platform_merchant_id. This can be used to identify if the payment was created by platform merchant.

If the payment was initialized by platform merchant, the merchant who is the owner of the payment should not be able to do any operations on the payment and vice versa.

So, we need those validations on payment intents to check if the current merchant can be allowed to perform those operations even if the authentication module allows it.

These payment ops are modified in the process.

Operation	Validation Added	Auth Used
Payment Approve	Yes	JWT + API Key
Payment Cancel	Yes	API Key
Payment Capture	Yes	API Key
Complete Authorize	No	Client Secret + API Key
Payment Confirm	No	Client Secret + API Key
Payment Reject	Yes	API Key
Payment Post Session Tokens	No	Publishable Key Auth
Payment Session	No	Publishable Key Auth
Payment Start	No	Merchant ID Auth
Payment Status	No	Client Secret + API Key + JWT
Payment Update	No	Publishable Key Auth + API Key
Payment Update Intent	Yes	API Key
Payment Incremental Authorization	Yes	API Key
Payment Session Update / Tax Calculation	No	Publishable Key Auth
Payment Create	No	API Key + JWT
Payment Intent Create	No	API Key + JWT
Payment Session Intent	No	Publishable Key Auth
Payment Get Intent	Yes	API Key
Payment Confirm Intent	No	Publishable Key Auth
Payment Get	Yes	API Key + JWT
Payment Capture V2	Yes	API Key + JWT
Payment Get Intent	Yes	API Key

Additional Changes

• This PR modifies the API contract
• This PR modifies the database schema
• This PR modifies application configuration/environment variables

Motivation and Context

Closes #7203.

How did you test it?

todo!()

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code
• I added unit tests for my changes where possible

[semanticdiff-com]

Review changes with  

Changed Files

File	Status
crates/router/src/core/payments/operations/payment_capture_v2.rs	39% smaller
crates/router/src/core/payments/operations/payment_get.rs	39% smaller
crates/router/src/core/payments/operations/payment_session_intent.rs	2% smaller
crates/router/src/core/payments/operations/payment_update_intent.rs	1% smaller
crates/router/src/core/payments/helpers.rs	0% smaller
crates/router/src/core/payments/operations/payment_approve.rs	0% smaller
crates/router/src/core/payments/operations/payment_cancel.rs	0% smaller
crates/router/src/core/payments/operations/payment_capture.rs	0% smaller
crates/router/src/core/payments/operations/payment_complete_authorize.rs	0% smaller
crates/router/src/core/payments/operations/payment_confirm.rs	0% smaller
crates/router/src/core/payments/operations/payment_confirm_intent.rs	0% smaller
crates/router/src/core/payments/operations/payment_get_intent.rs	0% smaller
crates/router/src/core/payments/operations/payment_post_session_tokens.rs	0% smaller
crates/router/src/core/payments/operations/payment_reject.rs	0% smaller
crates/router/src/core/payments/operations/payment_session.rs	0% smaller
crates/router/src/core/payments/operations/payment_start.rs	0% smaller
crates/router/src/core/payments/operations/payment_status.rs	0% smaller
crates/router/src/core/payments/operations/payment_update.rs	0% smaller
crates/router/src/core/payments/operations/payments_incremental_authorization.rs	0% smaller
crates/router/src/core/payments/operations/tax_calculation.rs	0% smaller
crates/router/src/routes/payment_methods.rs	0% smaller

[Narayanbhat166]

you can add a trait function to get the platform merchant id and then any generic that implements this trait can be passed to this function

[Narayanbhat166]

nit: you can use fp_utils::when