tsp - Use clientname as property name if it is specified

[dolauli]

This pull request updates the logic for generating model schemas in PowerShell by improving how property names are determined and allowing for client-specific naming overrides. The changes ensure that if a client name override is specified for a property, it will be used as the property's name in the generated schema.

Enhancements to property naming in model schema generation:

• Added retrieval of a client name override for each property using getClientNameOverride, specifically for PowerShell, in the getSchemaForModel function.
• Updated the property creation logic to use the client name as the property's name if it is specified, ensuring client-specific naming is respected in the schema.