Update kedro catalog create to use new /conf structure

[amandakys]

Description

Currently, the kedro catalog create command creates a new /catalog folder and adds a {pipeline-name}.yml inside (or just adds the file to the catalog folder if it aready exists.

Possible Implementation

Before

├── conf
    └── base
        └── catalog         
	    ├── data_science.yml     #blank files
        ├── catalog.yml              #blank files   
	└── parameters.yml           #blank files

After

├── conf
    └── base
	├── catalog_data_science.yml          #blank files
        ├── catalog.yml          #blank files   
	└── parameters.yml       #blank files

Calling kedro catalog create will:

• add catalog_{pipeline_name}.yml to /conf
• continue to do its current logic to create catalog entries for the corresponding pipeline