`export` Quick-fix should include `Create file 'path'`

[Luckey-Elijah]

Is your feature request related to a problem? Please describe.
With the part/part of ; directive quick fix feature, I sometimes expect the export directive to also have Create file 'path'; option in its quick fix menu.

Describe the solution you'd like
When the target URI doesn't exist (uri_does_not_exist) for an export directive, there should be a quick fix option: Create file 'path'.

Describe alternatives you've considered

A clear and concise description of any alternative solutions or features you've considered.

Additional context

No Create file 'bar.dart;' in Quick Fix menu.

But should create a file like:

[DanTup]

@bwilkerson do you see any reason not to support this for export as well as import? I'm not sure if it's deliberate or accidental (the use of ImportDirective here versus NamespaceDirective).

[bwilkerson]

I believe it's an oversight.

[DanTup]

This is fixed by dart-lang/sdk@419fd67 which will be included in a future Dart/Flutter SDK release.