Feature/grammar like usebruno lang

[marfranke]

Updated TextMate grammar to match (mostly) the @usebruno/lang grammar

• Add auth:* tag support (Resolves add highlighting for auth:*** #8)
• Add patch and body:sparql blocks
• Add syntax highlighting test file
• Some syntax highlighter styling adjustments

Edit:
Known differences to @usebruno/lang, that I am not planning to change right now (but I might in the future):

• Multiline Strings not supported by vscode syntax highlighting (Syntax Highlighting: Support Multiline Strings #15)
• vars withour pre-request/post-response not supported by @usebruno/lang
  • Used for collection.bru, I suppose that this is intended, so I am not planning to remove that unless someone gives me a good reason
• Blocks not starting at the begin of the line not supported by vscode syntax highlighting