refactor(payment_methods): refactor customer payment methods list v2 code to follow better code practices

[SanchithHegde]

Type of Change

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

Description

This PR includes refactors around the customer payment methods list v2 code to follow some of the practices we've started enforcing in the recent few months. Additionally, I've picked up some minor refactors along the way.

This PR contains the following changes:

• Adds a should_collect_cvv_during_payment column to the business profile v2 table to replace the {merchant_id}_requires_cvv config we used to read previously (and still do in v1) from the configs table.
• Renames the business_profile field to profile in the SavedPMLPaymentsInfo struct. (This follows the changes done in refactor: Rename business profile to profiles in api, diesel, domain, interface and error types #5877.)
• Renames the requires_cvv field to collect_cvv_during_payment in SavedPMLPaymentsInfo struct, to follow the new column added in the business profile v2 table.
• Passes profile to the form_payments_info() method instead of fetching it within the method. Eventually, we'd want to obtain the profile from the authentication layer instead, which would be passed forward.
• Moves the PaymentsMandateReference from the router crate to the diesel_models crate, and updates the connector_mandate_details field in the payment methods table to use PaymentsMandateReference instead of serde_json::Value in v2 code. (This should help reduce / prevent invalid data being stored in this column of the database.)
• Refactors the get_mca_status() function to avoid a possible database call (to fetch merchant connector accounts associated with a merchant / profile) happening within an iterator.
• Drops the metadata column from the payment methods table and API models in v2 code, since it isn't being actively used in v1 code anyway. Neither do any of our hosted environments have any useful data stored in that column.

The other minor refactors I took up along the way include:

• Improves the doc comment for the is_network_tokenization_enabled field in profile API models.
• Update the ExtendedCardInfoUpdate, ConnectorAgnosticMitUpdate and NetworkTokenizationUpdate enum variants of the ProfileUpdate domain model enum to have required fields instead of optional ones. (This is because these variants either enable something or not, and we always have the value to be updated in all cases.)
• Uses serialize_and_set_key_with_expiry() when storing payment method token in Redis instead of explicit JSON serialization happening in business logic.
• Replace usages of create_payment_method() (which only seemed to be updating the metadata field, and was thus confusing) with a correct apply_changeset() implementation. This change only affects MockDb implementation.

The PR can be reviewed one commit at a time, if that helps ease reviews.

Additional Changes

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

• This PR adds a new column in the business profile v2 database table and corresponding field in the business profile v2 API models.
• This PR drops the metadata column from the payment methods v2 database table and corresponding payment methods v2 API models.

Motivation and Context

This PR contains only a subset of the changes / improvements that can help us in arriving at the final implementation of the customer payment methods list v2 API. There are still a few more refactors pending, which would be taken up in subsequent PRs.

How did you test it?

Haven't been able to test these changes, there are still a couple of panics remaining in the customer payment methods list v2 code.

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/hyperswitch_connectors/src/connectors/deutschebank/transformers.rs	97% smaller
crates/router/src/core/payments.rs	94% smaller
api-reference/openapi_spec.json	48% smaller
crates/api_models/src/admin.rs	46% smaller
crates/router/src/db/payment_method.rs	38% smaller
api-reference-v2/openapi_spec.json	34% smaller
crates/router/src/types/payment_methods.rs	25% smaller
crates/router/src/core/payment_methods.rs	16% smaller
crates/diesel_models/src/payment_method.rs	13% smaller
crates/router/src/core/payment_methods/cards.rs	9% smaller
crates/hyperswitch_domain_models/src/business_profile.rs	7% smaller
crates/router/src/core/payments/tokenization.rs	1% smaller
Cargo.lock	Unsupported file format
crates/api_models/src/payment_methods.rs	0% smaller
crates/api_models/src/payments.rs	0% smaller
crates/diesel_models/src/business_profile.rs	0% smaller
crates/diesel_models/src/payment_attempt.rs	0% smaller
crates/diesel_models/src/schema_v2.rs	0% smaller
crates/hyperswitch_domain_models/src/merchant_connector_account.rs	0% smaller
crates/hyperswitch_domain_models/src/payment_methods.rs	0% smaller
crates/hyperswitch_domain_models/src/router_data.rs	0% smaller
crates/hyperswitch_domain_models/src/router_response_types.rs	0% smaller
crates/router/src/core/admin.rs	0% smaller
crates/router/src/core/payment_methods/transformers.rs	0% smaller
crates/router/src/core/payments/operations/payment_response.rs	0% smaller
crates/router/src/routes/payment_methods.rs	0% smaller
crates/router/src/services/authentication.rs	0% smaller
crates/router/src/types/api/admin.rs	0% smaller
crates/router/src/types/storage/payment_method.rs	0% smaller
v2_migrations/2024-08-23-112510_payment_methods_v2_db_changes/down.sql	Unsupported file format
v2_migrations/2024-08-23-112510_payment_methods_v2_db_changes/up.sql	Unsupported file format
v2_migrations/2024-08-28-081721_add_v2_columns/down.sql	Unsupported file format
v2_migrations/2024-08-28-081721_add_v2_columns/up.sql	Unsupported file format