Use consistent logging approach across all components

[tortmayr]

Currently in we use a mix of different logging approaches (console.log, injectable Logger instances etc.)
across all GLSP repositories. This makes it hard for adopters to implement a unified Logging approach e.g.
capturing all frontend GLSP log messages and writing them into a single file.

see also #1581

Let's quickly summarize the necessary changes:

• glsp-client:
  • Consistently use the injectable logger over console.log in injectable services
  • For stateless log (i.e. in plain functions) add an optional parameter so that we can pass-through a Logger instance.
• vscode-integration
  • webview: same change as in client
  • extension: Introduce a root level Logger interface and use it over console.log
• server-node:
  Make sure that we consistently use the provide Logger interface over console log
• theia-integration:
  • no changes necessary. console.logs are automatically handled by Theia's logger implementation
• Java-server:
  • Currently no changes necessary. We use standard logging libraries here (log4j)
• Eclipse-integration:
  - server: no changes necessary (log4j)
  - client/webview: same as in glsp-client