Support VSCode `source.fixAll`.

[Rapougnac]

Describe the bug In a project with a .vscode/settings.json file:

{
  "editor.codeActionsOnSave": {
    "source.fixAll": "explicit",
  }
}

This will not run custom_lint quick fixes on save, but successfully runs quick fixes of the base analyzer

To Reproduce Any custom lint that has a quick fix.

Expected behavior The most important quick fix should run