Basic support for REST services

[plule-ansys]

Even though the first release will be focused on gRPC, we should do the bare minimum for REST services. For library implementation, even though requests is common, there are other options such as httpx are widely used. We should not depend on any or all of them, but instead ensure that the pypim API makes it easy through:

• Relevant API entry to provide the endpoint and headers in a way that is directly translatable into the common libraries
• Documentation examples using them