Setup a Command Line Interface

[Stefterv]

This pull request will add command line arguments to the main Processing binary. Removing the need to publish separate binaries for additional functionality.

This will deprecate processing-java in favour of processing cli on linux.

Currently added functionality:

• cli Legacy hook for users of processing-java
• lsp Start the Language Server (for VSCode and Intellij)
• More to come, feel free to suggest more tools that could be added.

Fixes #1045 and Fixes #1047

[Stefterv]

Okay this is ready now.

Question, do we want to change this to provide processing on macOS instead of processing-java, in this way users on macOS can have access to Processing from the command line and not just the CLI, e.g. opening a Processing sketch by typing

$ processing /path/to/sketch/sketch.pde