Refactor: Rename project to browser_launcher and modularize launcher

[chouzz]

This Pull Request implements the renaming of the project from chrome_launcher to browser_launcher and refactors the core launcher logic for better modularity.

Changes:

• Project Renaming: Updated Cargo.toml, README.md, CHANGELOG.md, and all internal code references from chrome_launcher to browser_launcher.
• File Reorganization: Renamed src/chrome_launcher.rs to src/browser_launcher.rs.
• Modularity: Refactored Launcher to use a more modular approach for generating browser flags, making it easier to add support for non-Chromium browsers like Firefox or Safari in the future.
• CLI Update: Renamed the CLI tool to browser_launcher_cli.
• Code Cleanup: Renamed variables and structures (e.g., LaunchedChrome -> LaunchedBrowser) to be browser-agnostic.
• Verification: All unit and integration tests have been updated and pass successfully.

This refactoring ensures the codebase remains maintainable as more browser types are added.