Implement Check Availability Status Functionality

<UserStory> INV004: Check Availability Status </UserStory>

<Changes>
    1. Updated Controller to delegate getInventoryItem calls to InventoryManagementService.
    2. Implemented InventoryManagementService::getInventoryItem to fetch items from datastore by ID.
    3. Enhanced AdminMenu with checkStockAvailability function:
       - Accepts part ID as input.
       - Retrieves item details from Controller.
       - Displays item information (ID, part name, quantity) if found and active.
       - Handles inactive or missing items gracefully.
</Changes>

<Test>

  Precondition:
  1. Admin user is logged into the system.
  2. Inventory contains multiple items with unique IDs.
  3. DataStore is initialized and accessible.

  Steps:
  1. Navigate to Admin Menu and select "Check Stock Availability".
    - Verify that the system prompts for an Item ID.
  2. Enter a valid Item ID for an active item.
    - Verify that the system displays the item’s details including current quantity.
  3. Enter an Item ID that does not exist.
    - Verify that the system displays “Item not found”.
  4. Enter an Item ID for an inactive item.
    - Verify that the system does not display details and indicates the item is inactive.
</Test>

<Review>
Sreeja Reghukumar
</Review>

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.cpp

@@ -55,7 +55,7 @@ util::Map<std::string, const InventoryItem*> Controller::getInventoryItems()
 
 const InventoryItem* Controller::getInventoryItem(const std::string& inventoryItemID)
 {
-    return nullptr;
+    return m_inventoryManagementService.getInventoryItem(inventoryItemID);
 }
 
 void Controller::addInventoryItem(const std::string& partName, int quantity, double price)

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.h

@@ -2,6 +2,7 @@
 #include "Map.h"
 #include <string>
 #include "Enums.h"
+#include "InventoryManagementService.h"
 
 class Service;
 class ComboPackage;
@@ -14,6 +15,8 @@ class Notification;
 
 class Controller
 {
+private:
+    InventoryManagementService m_inventoryManagementService;
 public:
     bool login(const std::string& username, const std::string& password);
     void logout();

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/InventoryManagementService.cpp

@@ -1 +1,11 @@
 #include "InventoryManagementService.h"
+
+InventoryItem* InventoryManagementService::getInventoryItem(const std::string& inventoryItemID)
+{
+    int index = m_dataStore.getInventoryItems().find(inventoryItemID);
+    if (index != -1)
+    {
+        return m_dataStore.getInventoryItems().getValueAt(index);
+    }
+    return nullptr;
+}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp

@@ -1,6 +1,8 @@
+#include <iomanip>
 #include "AdminMenu.h"
 #include "InputHelper.h"
 #include "OutputHelper.h"
+#include "InventoryItem.h"
 
 void AdminMenu::showMenu()
 {
@@ -54,6 +56,23 @@ void AdminMenu::removeInventoryItem()
 
 void AdminMenu::checkStockAvailability()
 {
+	util::clear();
+	std::string itemId;
+	std::cout << "Enter the Item Id : ";
+	util::read(itemId);
+	const InventoryItem* selectedItem = m_controller.getInventoryItem(itemId);
+	if (selectedItem != nullptr)
+	{
+		if (selectedItem->getState() != util::State::INACTIVE)
+		{
+			std::cout << "Item Details\n";
+			std::cout << "---------------------------------------------\n";
+			std::cout << "Item ID      : " << selectedItem->getId() << "\n";
+			std::cout << "Part Name    : " << selectedItem->getPartName() << "\n";
+			std::cout << "Quantity     : " << selectedItem->getQuantity() << "\n";
+		}
+	}
+	util::pressEnter();
 }
 
 void AdminMenu::assignJob()