[FEATURE REQUEST] Add code blocks

[Schrodingdong]

• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Is your feature request related to a problem? Please describe.
As i use drawio for structuring SE projects, sometimes having a code snippet is a good thing to have beside some diagram.

Describe the solution you'd like
Having a code toggle for the text box component, potentially with language support. As an implementation i was thinking of using markdown, something similar to:

` ` `python
print("hello world")
` ` `

Describe alternatives you've considered
As of now, the only way to cleanly integrate the code is either:

• Manually indent / style the pasted text
• Use a code screenshot
• Do something similar to this

Additional context
This feature could be generalized as : "using markdown in text components"