Provide API for the new cutsom authentication management

[Thisara-Welmilla]

Feature

• https://github.com/wso2/product-is/issues/20809

This is to provide the API support for creating new custom authentication of one of following types to authentucatror user with external authentiaction service.

1. External User Account Authentication: This authenticator can authenticate federated users and provision them.
2. Internal User Account Authentication: This authenticator collects the identifiers and authenticates user accounts managed within the organization.
3. 2FA Authentication: This authenticator can only verify users in the second or subsequent steps of the login process.

Tasks:

• [ ] Update yaml files with new API capabilities.
• [ ] Improve authentication configuration API layer to support the custom authentication management
• [ ] Improve authentication configuration service layer to support the custom authentication management
• [ ] Unit tests for new improvements.