Added employee persistence, serialization, and file loading support

<SRS>SRS02 : Employee Management </SRS>

<Changes>
 - Implemented serialization and deserialization for Employee and GeneralEmployee models
 - Added FileManager integration to load employees from CSV files
 - Introduced ApplicationConfig entries for employee file paths
 - Updated Employee ID handling (getEmployeeId → getId) across project
 - Modified FileIO to auto-create file if not found instead of throwing exception
 - Added constructors for all employee types to support deserialization
 - Implemented loadEmployees in service and loadStates in controller
 - Ensured default admin creation if none exists during load
 - Added StringHelper utility for extracting numeric IDs
 - Extended Enums with string conversion and parsing utilities
 - Added initial CSV files for Employee and GeneralEmployee data
 - Improved login error message formatting and minor cleanup
 - Setup gitignore to not track csv files
</Changes>

Trenser.FileManager/Trenser.FileManager/FileIO.cpp

@@ -5,14 +5,14 @@ std::vector<std::string> FileIO::readAllLines(const std::string& path)
 {
     std::ifstream file(path);
     if (!file.is_open())
-        throw std::runtime_error("Failed to open file " + path);
-
-    std::vector<std::string> lines;
+    {
+        std::ofstream newFile(path);
+        newFile.close();
+        file.open(path);
+    }    std::vector<std::string> lines;
     std::string line;
-
     while (std::getline(file, line))
         lines.push_back(line);
-
     return lines;
 }
 

Trenser.FileManager/Trenser.FileManager/FileManager.h

@@ -1,7 +1,7 @@
 #pragma once
 #include "FileIO.h"
 
-template <typename T> using objects = std::map<int, std::shared_ptr<T>>;
+template <typename T> using objects = std::map<std::string, std::shared_ptr<T>>;
 
 template <typename T>
 class FileManager