Changes

Closes AST-52

This PR starts the implementation of the new logger functionality. As for now, the implementation and usage is solely focused on development.

Docs haven't been written as they should, and I would like to keep it that way for now, I will focus on writing towards the end of the works.

Here's the RFC: withastro/roadmap#1339

Here's what's been done:

• Updated the configuration to accept the new experimental flag
• Created a new logHandlers with
  • json, that returns a JSON logger
  • node, that returns the Node.js logger
  • console, that returns the console logger
  • compose, which allows to have multiple loggers together
  • New relative entrypoints, so that the specifiers can be easily imported
• The logger particular because we need it as early as possible, before we even start the dev server. So I used the same trick we use to import the configuration: we spawn a temporary vite server, specifically for loading the module. I exposed the inner function used by the loading system of the configuration, so that it's reusable for the logger.
• Created a small vite virtual module for the loading of the logger. We need a virtual module to support the compose API. The plugin for now is very minimal, however we will need to expand it for SSR. It will work very much like the middleware does.
• I established some patterns. Throughout the code base we were creating loggers in two ways, now we use only one way, using the create*Logger functions. This means that the destination becomes an implementation detail.
• I moved all the implementation inside the impls/ folder.
• I removed the _format type I created few days ago, because it's not needed anymore, because the architecture took a different course.
• The JSON logger uses a small regex to remove ANSI characters from the message. In another PR I plan to remove them from our logs, because using colours in our messages means that ANSI will be broadcast to downstream loggers too.

Testing

I updated the existing tests to use the new pattern. Green CI.

I tested locally the new compose API and the new json API.

Docs

N/A