feat(ses_email): add email services to hyperswitch

[Narayanbhat166]

Type of Change

• New feature

Description

This PR supports integrating multiple email services with hyperswitch. SES support is added in this PR.

Motivation and Context

There are two traits created in the external_services. In order to implement an email client, The EmailClient trait should be implemented.

How did you test it?

• Setup email service locally and send the email.

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
• I added a CHANGELOG entry if applicable

[SanchithHegde]

Other than that, looks good to me!

@Chethan-rao Can we also update the API key expiry task to send richer HTML emails, maybe in a separate PR?

hyperswitch/crates/router/src/workflows/api_key_expiry.rs

Lines 63 to 77 in bfa1645

	state
	.email_client
	.clone()
	.send_email(
	email_id.ok_or_else(|| errors::ProcessTrackerError::MissingRequiredField)?,
	"API Key Expiry Notice".to_string(),
	format!("Dear Merchant,\n
	It has come to our attention that your API key will expire in {expires_in} days. To ensure uninterrupted access to our platform and continued smooth operation of your services, we kindly request that you take the necessary actions as soon as possible.\n\n
	Thanks,\n
	Team Hyperswitch"),
	)
	.await
	.map_err(|_| errors::ProcessTrackerError::FlowExecutionError {
	flow: "ApiKeyExpiryWorkflow",
	})?;

[SanchithHegde]

Can we please use tera instead of using format!()?

[Narayanbhat166]

cc: @ThisIsMani

[Narayanbhat166]

No test cases need to be tested here.