Investigate the use of `keyring` to store API Keys

**Is your feature request related to a problem? Please describe.**
Ideally the `gallagher` token is provided by other mechanism (e.g environment variable) that is set by the user. Note that the API Key is generated by the Command Centre which is then passed as headers to the command centre (or via the proxy)

**Describe the solution you'd like**
Consider the use of a package like [`keyring`](https://pypi.org/project/keyring/) to store credentials from the Gallagher command centre.

More importantly we should debate if this is the right approach (the consideration here is that we have tui and cli applications which are public facing as opposed to developer centred).

**Describe alternatives you've considered**
NA

**Additional context**
Given the way keychains behave in Windows, we might have to provide substantial documentation for users to get this working properly.