Move resource/cmd under cmd/juju/resource

[anastasiamac]

Description of change

This is the first bit of work to bring resources commands under common architecture breaking away from components' one.
This PR contains straightforward, mechanical move of resource/cmd to cmd/juju/resource. It also brings in the fix for a panic (lp#1699607).

The follow up PRs will address actually removing registration of these commands from components/all and registering them as all other juju commands; using an accessor function on the list resources commands for resource listener; adding feature tests subset.

QA steps

All resources commands run the same - 'juju charm resources ', 'juju resources ', 'juju resources ', 'juju attach'.

Documentation changes

n/as as this is an internal change

Bug reference

First step to address: https://bugs.launchpad.net/juju/+bug/1706809
Brings in the fix into 2.3-alpha1 for: https://bugs.launchpad.net/juju/+bug/1699607

[mjs]

Thanks for breaking this up into manageable pieces.

[anastasiamac]

$$merge$$

[jujubot]

Status: merge request accepted. Url: http://juju-ci.vapour.ws:8080/job/github-merge-juju