Fix tab movement while running multiple actions

[Rosefield]

Summary of the Pull Request

Make sure to always synchronously set the selected tab. This way when changing tabs while running multiple actions further calls to _GetFocusedTab will return the correct one.

Edit #11146 discovered while trying to test this so while I fixed the case I wanted, things seem to be broken generally so it is hard for me to test if I broke anything else.

References

PR Checklist

• Closes Switching tab as part of running multiple actions does not focus tab immediately #11107
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Documentation updated. If checked, please file a pull request on our docs repo and link it here: #xxx
• Schema updated.
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

Ran the command specified in the issue and confirmed that the correct tab was focused and that the correct pane was zoomed.

[Rosefield]

While I'd like to get this in, I just want to make sure that #11146 gets attention too since that is a larger issue (and msftbot also took a vacation this weekend)