Add more tests (#870)

* tests: be more systematic when testing discrete column types

Still not covering all due to SQLite limitation

* tests: relations of models

* tests: model in another namespace gets correctly qualified

* tests: cover SoftDeletes trait

* tests: cover some variants of getter

tests/Console/ModelsCommand/migrations/____simple_table.php

@@ -0,0 +1,15 @@
+<?php declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class SimpleTable extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('simple', function (Blueprint $table) {
+            $table->bigIncrements('id');
+        });
+    }
+}