Introduce new authenticator properties: DefinedBy

[Thisara-Welmilla]

Feature

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

With this following properties will be introduce to the authenticator configs and Application Authenticators.

• DefinedBy - to indicate whether the authenticator is system-defined or user-defined.
  1. SYSTEM: Sytem defined authenticators, all the existing authenticators are this type.
  2. USER: User defined authenticators, all the custom authenticators of authentication extension come under this type.

[Thisara-Welmilla]

Related PRs:

• https://github.com/wso2/carbon-identity-framework/pull/5991
• https://github.com/wso2/carbon-identity-framework/pull/5990
• https://github.com/wso2/identity-api-server/pull/679
• https://github.com/wso2/carbon-identity-framework/pull/6029

Fix unit tests:

• https://github.com/wso2/carbon-identity-framework/pull/6017

Integration tests:

• https://github.com/wso2/product-is/pull/21315
• https://github.com/wso2/product-is/pull/21381