[Feature] Added custom "blank" and "filled" Blade directives

[alexjustesen]

📃 Description

This PR adds custom Blade templates @blank and @filled to improve readability as it was rejected in the core: laravel/framework#51561

🪵 Changelog

➕ Added

• @blank and @filled Blade templates to improve readability.

🤔 Usage

Using @blank() in a view:

// before
@if (blank())
    i am blank
@endif

// after
@blank($var)
    i am blank
@endblank

Using @filled() in a view:

// before
@if (! blank($var))
    i am not blank (filled)
@endif

// or

@if (filled($var))
    i am not blank (filled)
@endif

// after
@filled($var)
    i am not blank (filled)
@endfilled