Add containers project with CMake setup and array-related functionality

- Implement `printArrayAtPosition` in `functions.cpp` with input validation.
- Created `main.cpp` to demonstrate array operations using C arrays and `std::vector`.
- Updated `ClassA` and `IComparable` with constructors, destructors, and deep copy logic.
- Adjusted IntelliJ project configuration for new containers module.

cpp/containers/CMakeLists.txt

@@ -0,0 +1,9 @@
+cmake_minimum_required(VERSION 4.1)
+project(containers)
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_FLAGS -pedantic-errors)
+
+add_executable(containers
+        main.cpp
+        functions.cpp)