Runner Panel: Add customizable color-coding

[adam-coster]

Now that we have a custom webview for displaying GameMaker projects' stdio, we can fancy up the logs to make them easier to grok.

Any given project will have different log formats, and formats for a given project will also change over time, so this needs to be a highly general system on the VSCode side. Configs will need to be specified at the project level, either via VSCode's configs or via stitch.config.json. Since this is specific to VSCode, the former is probably better.

VSCode's Problem Matcher paradigm is a good reference for this idea, though we have a more specific problem here (and since we aren't using a terminal we have a lot more flexibility in functionality).

[adam-coster]

Implemnted! Config settings via stitch.config.json > gameConsoleStyle, allowing for regex-based styling. No interactivity yet, but that's coming.