Addon Base: Multiple Service Provider (Organization)

[JohnathonKoster]

Create a sustainable setup for allowing the following when developing Meerkat for Statamic 3:

• Allow for multiple service providers (to organize what's loaded, and when)
• Allow for service providers to indicate that they should only be loaded for web, control panel, or command line requests (or any combination)

Each Service Provider should be able to provide it's own routes, etc. where appropriate (as if it were the main Statamic 3 Addon Service Provider)

This will involve detecting the following run-time contexts:

• [x] Web
• [x] Statamic Control Panel
• [x] Artisan Console (CLI)