Quick fix "Use imported library ... with prefix ..." should update show combinator

[stereotype441]

Reproduced at 3636c8a using VSCode.

Start with the following code:

import 'dart:math' as math show log; // (1)

main() {
  print(sqrt2); // (2)
}

This code has a compile-time error at (2) (undefined_identifier).

Trigger quick fixes at that point, and select the fix "Use imported library 'dart:math' with prefix 'math'".

This causes line (2) to change to:

  print(math.sqrt2); // (2)

Which, unfortunately, still has a compile-time error, since the import at (1) doesn't show sqrt2.

It would be nice if the quick fix also updated the import's show combinator.

[FMorschel]

Related to Dart-Code/Dart-Code#5238.
Somewhat to #36737.