OpenAPI specification and API Adjusts (#356)

Introduced an OpenAPI specification.
Updated API handlers to use the specification types.

Added patch operation for rules and groups
and methods to the account manager.

HTTP PUT operations require id, fail if not provided.

Use snake_case for HTTP request and response body

management/server/http/api/cfg.yaml

@@ -0,0 +1,5 @@
+package: api
+generate:
+  models: true
+  embedded-spec: false
+output: types.gen.go