Add SLAController and related routes, update create view

Introduced a new SLAController for handling SLA-related operations, including necessary routes and breadcrumb updates. Replaced the select input with a text input in the create view for better flexibility.

database/migrations/2024_10_28_095337_create_s_l_as_table.php

@@ -0,0 +1,27 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('sla', function (Blueprint $table) {
+            $table->id();
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('sla');
+    }
+};