Fix extension reloading for local bundle extensions

[nickrum]

Fixes #17694

[paescuj]

@nickrum I assume this is the preferred solution over #18278?

[paescuj]

Nothing to worry about but do you think we can optimize the following points? Can create an issue in that case.

• When rebuilding a bundle the reload info is always displayed twice:

  [20:34:09.262] INFO: Reloading extensions
  [20:34:34.583] INFO: Reloading extensions
  

• When scaffolding or removing a bundle some warnings are displayed because the bundle is incomplete for some amount of time:

  [20:34:34.591] WARN: Couldn't register bundle "directus-extension-test"
  [20:34:34.591] WARN: Cannot find module '<redacted>/api/extensions/directus-extension-test/dist/api.cjs' imported from <redacted>/api/dist/extensions.js
  

• Although the extension couldn't be registered it still appears in the list of loaded extensions:

  [11:38:58.565] INFO: Loaded extensions: directus-extension-test
  

[nickrum]

When rebuilding a bundle the reload info is always displayed twice

This is due to the API watching both api.js as well as app.js for changes. We could debounce the reload, but that wouldn't help if one entrypoint takes way longer to be build than the other.

When scaffolding or removing a bundle some warnings are displayed because the bundle is incomplete for some amount of time

Hmm, that's not so nice, indeed! I wonder what we can do about it, though, unless we want to disable that warning as a whole 🤔

Although the extension couldn't be registered it still appears in the list of loaded extensions

That's more or less expected with the current system as loading an extension just means that it was found and registration of an extension means that the API imported it. We could tweak the wording or filter the list of loaded extensions based on if they were registered successfully.