[9.x] Add support for cursor and LazyCollection on scout.

[crynobone]

At the moment Laravel Scout doesn't utilised cursor or LazyCollection which could be useful when searching large set of data. This PR bring the ability to use get() or cursor() from Eloquent query builder whenever possible.

• Add Laravel\Scout\Searchable::queryScoutModelsByIds() to return Illuminate\Database\Query\Builder.
• Add Laravel\Scout\Builder::cursor() to return results as LazyCollection
• Add Laravel\Scout\Engines\Engine::lazyMap() to map to LazyCollection

Signed-off-by: Mior Muhammad Zaki crynobone@gmail.com