Reduce the number of schema objects

ODL apidoc implementation creates a lot of schemas objects even for simple models like my-yang@2022-10-06.yang. This file contains just one container with one leaf and we have 6 schemas objects instead of 2.

We can see that petstore example is using the same schemas object for PUT, POST, XML, JSON, etc. Thus in ODL, we are creating a lot of objects without any reason to do so (except of wasting memory).