feat(core) : Add support for v2 payments get intent using merchant reference id

[srujanchikke]

Type of Change

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

Description

Work in progress

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?

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/routes/lock_utils.rs	80% smaller
crates/router/src/routes/app.rs	20% smaller
crates/router/src/db/kafka_store.rs	8% smaller
crates/api_models/src/payments.rs	0% smaller
crates/diesel_models/src/query/payment_intent.rs	0% smaller
crates/hyperswitch_domain_models/src/payments/payment_intent.rs	0% smaller
crates/router/Cargo.toml	Unsupported file format
crates/router/src/core/payments.rs	0% smaller
crates/router/src/routes/payments.rs	0% smaller
crates/router_env/Cargo.toml	Unsupported file format
crates/router_env/src/logger/types.rs	0% smaller
crates/storage_impl/src/mock_db/payment_intent.rs	0% smaller
crates/storage_impl/src/payments/payment_intent.rs	0% smaller

[srujanchikke]

#7123