Add SetVoidResult to Focus handlers with tests

[anddrzejb]

Pull request description

Fixes #522

Adds to SetVoidResult to FocusAsyncInvocationHandler & FocusOnNavigateHandler. Without it, if consumer was awaiting the result of the call to respective js, a Task with Status = WaitingForActivation was returned. This way the call was never finishing. Adding SetVoidResult markes the returned task as completed.

Tests

I figured the best way to find out if task was completed was to add a boolean after the call in question. If task was completed, the boolean is set to true. That boolean property is later asserted in the test. In both cases the tests do not pass without SetVoidResult.

Testing this in FocusOnNavigateHandler required me to create a derived component, so I can actually add the boolean property.

PR meta checklist

• Pull request is targeted at main branch for code
  or targeted at stable branch for documentation that is live on bunit.dev.
• Pull request is linked to all related issues, if any.
• I have read the CONTRIBUTING.md document.

Code PR specific checklist

• My code follows the code style of this project and AspNetCore coding guidelines.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• I have updated the appropriate sub section in the CHANGELOG.md.
• I have added, updated or removed tests to according to my changes.
  • All tests passed.

[egil]

Looks good to me.

Just add a bullet point to the Unreleased/Fixed section in the CHANGELOG.md file about this.

[anddrzejb]

Done. I can't figure out why ubuntu action was failing.

[egil]

Done. I can't figure out why ubuntu action was failing.

Looks like a test host failure. I'll rerun and let's see if that doesn't help.

[egil]

Thank you very much for your help on this. Good catch with this bug!