Add hls-cabal-project-plugin for cabal.project file support

[GirishDewangan06]

Description

This PR adds a new plugin hls-cabal-project-plugin that provides language server support for cabal.project files. The plugin is designed to enhance the Haskell Language Server's capabilities by providing specialized support for project configuration files.

Features

• Basic plugin structure and configuration
• Support for parsing and validating cabal.project files
• Integration with the main HLS plugin system

Future Enhancements

The plugin is structured to support future additions of:

• Completions for keywords, file paths, and enum values
• Diagnostics for syntax errors and invalid configurations
• Syntax highlighting for cabal.project files

Testing

• Basic plugin structure has been tested
• Integration with HLS plugin system verified

Related Issues

This implementation addresses the need for better support of cabal.project files in HLS, similar to the existing support for .cabal files.

[fendor]

Hi, thank you for your PR!

I presume this is a Draft PR, and you should mark it as such :)