Support preserving capitalisation for models and columns

[Thrasi]

Describe the feature

generate_model_yaml.sql lower cases every model and column name.
add support for preserving capitalisation.

Describe alternatives you've considered

Add two optional parameter to the macro, one for model names and one for column names to control the behaviour.

Who will this benefit?

Anyone working with a database with a naming standard where capitalisation is important. This is related to the issue related to generate_source_yaml.

Are you interested in contributing this feature?

Yes, I have what I believe is a working solution to the issue.

[dbeatty10]

Thanks for reaching out @Thrasi !

This looks like the same/similar thing as requested in #175, so I'm going to close this one as a duplicate.

Would welcome any additional thoughts you have over there. Since you closed your draft PR, would also be interested to learn if you came up with a workaround.