Add quick fix to add import with prefix

[bwilkerson]

There is a quick fix to add an import for an unknown type name, but when the type name is qualified the only fix suggestion is to define the class (which is not a valid fix and shouldn't be suggested). For example, enter the following code into a Dart file:

class C {
prefix.String s;
}

and place the cursor inside the identifier 'String'. It would be nice if one of the suggested fixes was to add an import (of dart:core, in this case) with the given prefix.

[srawlins]

I like this idea.

[FMorschel]

Related to:

• Import library with prefix assist #55863
• Add a quick fix to import libraries with prefixes when the library name matches #41515