Fixed crash when key contains BackedEnum

[KentarouTakeda]

resolves #168, resolves: #176

Fixed an issue where relationships could not be retrieved if a composite key contained a value casted to an enum.

PHP 8.1, Laravel 8, supports the ability to cast specific column values ​​to BackedEnum and reference them from an Eloquent model.

Reference:
https://laravel.com/docs/8.x/eloquent-mutators#enum-casting

However, our library did not support this feature. If a BackedEnum value is included as part of a composite key, retrieving a relationship would crash.

• Lazy loading of HasMany relationships
• Eager loading of HasMany relationships
• Eager loading of BenlongTo relationships

All of these issues are caused by our library assuming that the key value can be interpreted as a string. In addConstraints before query execution and match after execution, the key is evaluated as a string using implode or array_unique.

An attribute cast to a BackEnum has its backed value before the cast, so evaluating $backedEum->value instead of $backedEnum in the offending operation will solve this issue.

[KentarouTakeda]

@topclaudy
Hi! I'm excited to find the great library. Could you please take a look at this pull request?

[topclaudy]

Thanks @KentarouTakeda Released in 2.4.0