feat: add case sensitivity option for generate_model_yaml model and column names

[JiriMerunka]

Problem

generate_model_yaml does not generate output correctly when model or column name contain uppercase character

Solution

Adds case_sensitive_models and case_sensitive_cols parameters to generate_model_yaml macro.
They allow to specify whether to convert model or column names to lower case or not.

Checklist

• This code is associated with an issue 263 which has been triaged and accepted for development.
• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have updated the README.md (if applicable)