Spike: Investigate theming in Monaco editor

[andrew-ronaldson]

Related to patternfly/chatbot#424
TLDR there is a code block and code editor message type in the ChatBot and we'd like to consolidate it by just shipping code editor.

The problem is with theming where if we use the inverse token to get a dark background in light theme it will be a white background on dark theme which isn't ideal. Preferably we would like to investigate the theming capability of the code editor so it can be more flexible for those that wish to choose their own preference.

Links
monaco-editor Docs https://www.npmjs.com/package/@monaco-editor/react
Stack overflow link https://stackoverflow.com/questions/44766624/custom-background-color-in-monaco-editor