Add a configure parameter to handle the inventory file location

[sheenaajay]

Use Case

Add a configure parameter to handle the inventory file location.
Hence for any change in the the file location can be done by changing the variable value instead of updating all the hardcoded values in the litmus lib files, which will make the maintenance easier.

Describe the Solution You Would Like

Similar approach is done at provision_service where we can update the default values at one place
https://github.com/puppetlabs/provision_service/blob/main/backend/lib/configuration/backend_configuration.rb#L56