Improve alphaTex coding assistence

[Danielku15]

This issue is tracking improvements related to #2303

The overall idea of the changes are:

• Build the foundation for a advanced IDE/code editor
• Provide a TextMate grammar for use in Monacco (VS Code editor)
• Provide an LSP with features like:
  • Diagnostic Reporting (lexer/parser/semantic)
  • Semantic Highlighting
  • Documentation Overlays (for effects, meta tags etc.)
  • Auto Completion
  • Quick Fixes (for warnings/hints).
  • (Maybe formatting)
• Build a base extension for VS Code for editing .atex files
  • Editor Features
  • Maybe a preview window?