Uncommented base migration
* Refactored the way items kinds are handled
* Added ArchItemKind (See previous bullet) model
* Added ArchProvided model (The base. Lots of possible stuff with this architecture
* Updated item kinds name / icons
* Added provider field to items table
* Added default provider
* Implemented Provider check (only Youtube for now)
* Implemented first AJAX route: /ajax/provider-type