feat(payment_methods): add external vault connector service

[Sakilmostak]

Type of Change

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

Description

TODO

Additional Changes

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

Motivation and Context

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

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Changed Files

File	Status
crates/hyperswitch_domain_models/src/router_data_v2.rs	93% smaller
crates/router/src/core/payment_methods/transformers.rs	83% smaller
crates/common_enums/src/connector_enums.rs	79% smaller
crates/hyperswitch_domain_models/src/types.rs	71% smaller
crates/hyperswitch_interfaces/src/connector_integration_v2.rs	63% smaller
api-reference-v2/openapi_spec.json	50% smaller
api-reference/openapi_spec.json	50% smaller
crates/hyperswitch_interfaces/src/api.rs	42% smaller
crates/router/src/types.rs	29% smaller
crates/hyperswitch_domain_models/src/router_request_types.rs	20% smaller
crates/router/src/core/payment_methods.rs	16% smaller
crates/router/src/types/payment_methods.rs	13% smaller
crates/hyperswitch_interfaces/src/conversion_impls.rs	7% smaller
crates/router/src/core/payment_methods/vault.rs	6% smaller
crates/router/src/types/api.rs	1% smaller
crates/router/src/core/utils.rs	1% smaller
crates/hyperswitch_connectors/src/default_implementations.rs	1% smaller
crates/api_models/src/enums.rs	0% smaller
crates/common_enums/src/enums.rs	0% smaller
crates/connector_configs/src/connector.rs	0% smaller
crates/hyperswitch_connectors/src/default_implementations_v2.rs	0% smaller
crates/hyperswitch_domain_models/src/business_profile.rs	0% smaller
crates/hyperswitch_domain_models/src/router_data_v2/flow_common_types.rs	0% smaller
crates/hyperswitch_domain_models/src/router_flow_types.rs	0% smaller
crates/hyperswitch_domain_models/src/router_flow_types/vault.rs	0% smaller
crates/hyperswitch_domain_models/src/router_response_types.rs	0% smaller
crates/hyperswitch_interfaces/src/api/vault.rs	0% smaller
crates/hyperswitch_interfaces/src/api/vault_v2.rs	0% smaller
crates/router/src/core/admin.rs	0% smaller
crates/router/src/core/payments/flows.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/api.rs	0% smaller
crates/router/src/types/api/vault.rs	0% smaller
crates/router/src/types/api/vault_v2.rs	0% smaller
crates/router/src/types/transformers.rs	0% smaller