class-generator creates incorrect filename for MaaSModelRef resource

[SB159]

Describe the bug
When generating a resource wrapper using class-generator, the generated filename for the MaaSModelRef resource is incorrect. The generator creates the file: ocp_resources/maa_s_model_ref.py, However, the expected filename should be: ocp_resources/maasmodelref.py

To Reproduce
Steps to reproduce the behavior:
1.Run the command: class-generator --kind MaaSModelRef
2.The generated file is: ocp_resources/maa_s_model_ref.py
3.
4.

Expected behavior
The generator should create the file: without splitting MaaS into maa_s.

Additional context
Add any other context about the problem here.