Fixes and features

Quite a few more changes, many under-the-hood restructures and fixes.

• Breaking change (of features almost no one has started using): remotes are now hosts and are stored in a geneos-hosts.json file in the user's config directory and not in their own remotes/ directory. If you are one of the few who have used remotes then you have to re-add all the remotes as no conversion process is supported
• Download support (init and install) supports authentication for resources.itrsgroup.com and also supports downloads from nexus.itrsgroup.com for internal use
• A number of flags for commands have been changed, rationalised and re-thought