Add installation and packaging targets

[prasithbasky]

Description

This PR updates the CMake configuration to support installation and packaging via CPack. The following changes have been implemented:

• Install Targets: Added install commands to CMakeLists.txt for the cpackexample executable, cpackexamplelib library, and associated header files using GNUInstallDirs.
• CPack Configuration: Created cmake/CPackConfig.cmake to generate .tar.gz and .deb packages.
• Debian Specifics: Configured CPack to use the standard Debian naming scheme (DEB-DEFAULT) and enabled automatic dependency detection (shlibdeps).
• Optimization: Enabled CMAKE_INSTALL_DO_STRIP to strip symbols and reduce the final package size.

How to Test

To verify these changes, please follow these steps using the provided Docker environment:

### 1. Build and Run the Docker Container
```bash
docker build -t cpack-image .
docker run --rm -it --mount type=bind,source="$(pwd)",target=/mnt/cpack-exercise cpack-image

2. Build and Package

Inside the Docker container:

cd /mnt/cpack-exercise
rm -rf build && mkdir build && cd build
cmake ..
make -j4
make package

3. Verify Installation and Execution

   apt install ./cpackexample_0.1.0-1_amd64.deb
   cpackexample

Lintian Output

lintian ./cpackexample_0.1.0-1_amd64.deb