support specific swagger or openapi security and validator configuration

[stevehu]

Previously, each service instance can only support one chain of middleware handlers and that means you can only choose one framework per instance. With the multiple chain support introduced in 1.5.17, we can have multiple frameworks in the same instance. For example, both swagger and openapi in the same instance with different specifications for v1 and v2. OpenAPI and GraphQL support in the same instance etc. To support the new feature, we need to separate the security and validator config files in case different frameworks have different configurations. For backward compatibility, the generic shared security.yml and validator.yml are still used if all frameworks are sharing the same config or there is only one framework available on the server instance.

The logic is to use framework specific config {framework}-security.yml or {framework}-validator.yml first and then fallback to security.yml or validator.yml