Check if command already exists before attempting to create

[kodejuice]

These changes makes sure a command doesn't exist before attempting to create it, if it does the user gets a command already exists message.

I lost a lot of uncommited work in a project of mine because i mistakenly ran $ cobra add .., this pull request aims to fix that.

[CLAassistant]

All committers have signed the CLA.

[github-actions[bot]]

This PR is being marked as stale due to a long period of inactivity

[kodejuice]

.....