chore(phpstan): enable phpstan in bundled extensions (#3667)

* feat(phpstan): pick up extended model relations typings
* feat(phpstan): pick up extended model date attributes
* feat(core): introduce `castAttribute` extender
Stops using `dates` as it's deprecated in laravel 8
* feat(phpstan): pick up extended model attributes through casts
* fix: extenders not resolved when declared namespace
* fix(phpstan): new model attributes are always nullable
* chore(phpstan): add helpful cache clearing command
* Apply fixes from StyleCI
* chore: improve extend files provider logic
* chore: rename `castAttribute` to just `cast`
* chore: update phpstan package to detect `cast` method
* chore: enable phpstan in bundled extensions
* chore: rebasing conflicts
* chore: rebasing conflicts
* chore: typings for latest 1.7 changes

Signed-off-by: Sami Mazouz <sychocouldy@gmail.com>

extensions/approval/extend.php

@@ -28,15 +28,17 @@ return [
 
     // Discussions should be approved by default
     (new Extend\Model(Discussion::class))
-        ->default('is_approved', true),
+        ->default('is_approved', true)
+        ->cast('is_approved', 'bool'),
 
     // Posts should be approved by default
     (new Extend\Model(Post::class))
-        ->default('is_approved', true),
+        ->default('is_approved', true)
+        ->cast('is_approved', 'bool'),
 
     (new Extend\ApiSerializer(BasicDiscussionSerializer::class))
         ->attribute('isApproved', function ($serializer, Discussion $discussion) {
-            return (bool) $discussion->is_approved;
+            return $discussion->is_approved;
         }),
 
     (new Extend\ApiSerializer(PostSerializer::class))