refactor(email): Add recipient emails in email config

[ThisIsMani]

Type of Change

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

Description

• This PR add recipient emails for recon and prod_intent under email config.

Additional Changes

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

config/config.example.toml
config/deployments/env_specific.toml
config/development.toml
config/docker_compose.toml
loadtest/config/development.toml

Motivation and Context

Closes #5963.

How did you test it?

curl --location 'http://localhost:8080/user/data' \
--header 'Content-Type: application/json' \
--header 'Authorization: ••••••' \
--data '
{
    "ProdIntent": {
        "is_completed": true,
        "legal_business_name": "test",
        "business_label": "test",
        "business_location": "US",
        "display_name": "test",
        "poc_email": "test",
        "business_type": "test",
        "business_identifier": "test",
        "business_website": "test",
        "poc_name": "test",
        "poc_contact": "test",
        "comments": "test"
    }
} 
'

The above API should send prod intent email to configured prod intent 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

[semanticdiff-com]

Review changes with SemanticDiff.

Analyzed 8 of 13 files.

Overall, the semantic diff is 32% smaller than the GitHub diff.

	Filename	Status
❔	loadtest/config/development.toml	Unsupported file format
✔️	crates/router/src/utils/user/dashboard_metadata.rs	46.09% smaller
✔️	crates/router/src/services/email/types.rs	59.29% smaller
✔️	crates/router/src/core/recon.rs	4.1% smaller
✔️	crates/router/src/core/user/dashboard_metadata.rs	Analyzed
✔️	crates/router/src/consts/user.rs	Analyzed
✔️	crates/router/src/configs/secrets_transformers.rs	Analyzed
✔️	crates/router/src/configs/settings.rs	Analyzed
✔️	crates/external_services/src/email.rs	Analyzed
❔	config/config.example.toml	Unsupported file format
❔	config/development.toml	Unsupported file format
❔	config/docker_compose.toml	Unsupported file format
❔	config/deployments/env_specific.toml	Unsupported file format