Clean up Eloquent folder a bit

- Re-arrange namespaces
- Properly indent params in DocBlocks
- Add missing params in DocBlocks
- Add dependencies in to some function parameters (Mostly Builder classes)
- Fix some incorrect return types
Replace incorrect return type
Fix type-hint.
Allow non-integers in sync.
Extract the pivot model creation to the related model for customization.
Set startOfDay on Y-m-d attributes.