support rejected slot from $slots

[GerardRodes]

I'd like to introduce a rejected slot but without scoped data

What kind of change does this PR introduce? (check at least one)

• Bugfix
• [x ] Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• [ x] No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)
• All tests are passing
• New/updated tests are included

If adding a new feature, the PR's description includes:

• [ x] A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)

Other information:

[codecov-io]

Codecov Report

Merging #16 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #16   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           2      2           
  Lines          46     47    +1     
  Branches       16     17    +1     
=====================================
+ Hits           46     47    +1

Impacted Files	Coverage Δ
src/index.js	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7b6d98d...e3a670c. Read the comment docs.

[posva]

This is indeed a good feature. Could you add a test please? It should be very similar to the one for the default scoped slot

[posva]

This is already supported when using latest Vue version :)