[TIMOB-27764] Add support for loading global CLI plugins from local directory

This would allow a developer to put a global plugin in the local plugins directory and have it use this. The global plugin would need to be named "titanium-global-plugin.js" Currently the first batch of hooks used by the CLI cannot be used by local plugins and can only be used by global plugins. Doing this would remove one of the last obstacles for using global plugins as it could then be used on a per-project basis, if desired.