Add/improve debugging printing

[hrszpuk]

There already exists some debug printing but it is very minimal.

There is a log library in core that could be used to improve the messages.

Checklist:

• Lexer
• Parser
• Config functions
• Write functions
• Read functions

May want to change the structure of some of the code to make logging easier (like adding a new_token function so the log can easily show when a new token is created).