Support for Semantic highlight/token

[GrayJack]

If the language server implements semantic highlighting there some theming advantages to semantic tokens that users and theme-makers could use, like:

• Function parameter names can be highlighted differently within the function body
• It's possible to add several modificators for tokens to could be used to colorize differently for better context (example: a const variable can have a const modifier and colorized differently as a constant color of the theme)

[hellmrf]

+1

[evanphilip]

Thank you for your work on this @FelipeLema . I was unsuccessful in figuring out how to switch my extension to your fork, so I'll wait for the PR. Can't wait to try it!