Add common functions to namespace

[athowes]

the common CLI functions are good examples of things we might want in the namespace as we use them a lot

Originally posted by @seabbs in #329 (comment)

Also could do this for checkmate functions and anything else which seems appropriate.

Am I right in thinking never to use @importFrom in the roxygen next to the function and always centralised?

[seabbs]

Am I right in thinking never to use @importFrom in the roxygen next to the function and always centralised?

I think if we are importing something because it is used a lot in one function that could be a good arg for doing it next to the function but if its because we use it several times across functions it might be clearer to centralise. I don't think it makes much different as you can just look at the namespace so whatever you would rather and can keep track of