Add cross-platform support for determining the executable directory and output directory configuration

[eharquin]

Title: Add Cross-Platform Support for Determining the Executable Directory and Configurable Paths

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Description

This PR introduces the following enhancements and fixes:

1. Cross-Platform Executable Directory Detection:

   • Replaced hardcoded paths with a dynamic method to retrieve the directory of the executable.
   • Added platform-specific logic:
     • Windows: Used GetModuleFileNameA to retrieve the executable's directory.
     • Linux/macOS: Used dirname() from <libgen.h>.

2. New -d Option for Configurable Data Directory:

   • Introduced a -d <data_dir> option to specify the data directory path at runtime.
   • If no -d option is provided, the program defaults to a data directory relative to the executable's directory.

3. Output Directory Configuration:

   • Introduced a -o <output_dir> option to specify the output directory for generated files.
   • If no -o option is provided, the default output directory (output/) is used.

4. Improved Flexibility:

   • Removed the dependency on hardcoded paths like ../data. The data directory is now dynamically resolved based on the -d option or the executable's directory.

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How to Test

1. Build and Run:

   • Compile the project on both Linux/macOS and Windows platforms.
   • Run the executable with the -d and -o options:

     ./garamon_generator -d /custom/data/path -o /custom/output/path conf/example.conf

   • Verify that the data files are accessed from /custom/data/path and the output files are generated in /custom/output/path.

2. Default Behavior:

   • Run the executable without the -d or -o options:

     ./garamon_generator conf/example.conf

   • Verify that the data directory defaults to ../data (relative to the executable) and the output files are generated in output/.

3. Cross-Platform:

   • Ensure that the logic for detecting the executable directory and resolving the data directory works correctly on both Windows and Linux/macOS.

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Additional Context

• This PR resolves issues related to portability by removing dependencies on hardcoded paths.
• The new -d option enhances usability by allowing the user to specify the data directory path dynamically.

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Checklist

• Verified functionality on Linux/macOS.
• [] Verified functionality on Windows.
• Added cross-platform support for the executable directory.
• Added -d option for configurable data directory.
• Tested with different data and output directory configurations.
• [] Ensured backward compatibility with existing behavior.