[4.x] Clean up expired impersonation tokens instead of just aborting, add command for cleaning up expired tokens (#1387)

This PR makes the expired/invalid tenant impersonation tokens get
deleted instead of just aborting with 403.

The PR also adds a command (ClearExpiredImpersonationTokens) used like
`php artisan tenants:purge-impersonation-tokens`. As the name suggests,
it clears all expired impersonation tokens (= tokens older than
`UserImpersonation::$ttl`).

Resolves #1348

---------

Co-authored-by: Samuel Štancl <samuel@archte.ch>

src/Commands/PurgeImpersonationTokens.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\Commands;
+
+use Illuminate\Console\Command;
+use Stancl\Tenancy\Features\UserImpersonation;
+
+/**
+ * Clears expired impersonation tokens.
+ *
+ * Tokens older than UserImpersonation::$ttl are considered expired.
+ *
+ * @see Stancl\Tenancy\Features\UserImpersonation
+ */
+class PurgeImpersonationTokens extends Command
+{
+    protected $signature = 'tenants:purge-impersonation-tokens';
+
+    protected $description = 'Clear expired impersonation tokens.';
+
+    public function handle(): int
+    {
+        $this->components->info('Deleting expired impersonation tokens.');
+
+        $expirationDate = now()->subSeconds(UserImpersonation::$ttl);
+
+        $impersonationTokenModel = UserImpersonation::modelClass();
+
+        $deletedTokenCount = $impersonationTokenModel::where('created_at', '<', $expirationDate)
+            ->delete();
+
+        $this->components->info($deletedTokenCount . ' expired impersonation ' . str('token')->plural($deletedTokenCount) . ' deleted.');
+
+        return 0;
+    }
+}