[4.x] Improve id generators (#1300)

* add RandomIntGenerator

* remove string assertions

* make int ranges configurable

* update test to use min & max

src/UniqueIdentifierGenerators/RandomIntGenerator.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Stancl\Tenancy\UniqueIdentifierGenerators;
+
+use Illuminate\Database\Eloquent\Model;
+use Stancl\Tenancy\Contracts\UniqueIdentifierGenerator;
+
+/**
+ * Generates a cryptographically secure random integer for the tenant key.
+ */
+class RandomIntGenerator implements UniqueIdentifierGenerator
+{
+    public static int $min = 0;
+    public static int $max = PHP_INT_MAX;
+
+    public static function generate(Model $model): string|int
+    {
+        return random_int(static::$min, static::$max);
+    }
+}