fix(commad): close #11346, use available number to label when create …

[yiliang114]

What it does

close #11346

after change:

How to test

1. yarn & yarn browser build & yarn browser start.
2. Open http://localhost:3000/ and open any workspace.
3. Use alt + n to call NEW_FILE command some times, we can see tab named Untitled-${index} one by one. The number in label is start from 1 like vscode.
4. Call NEW_FILE command again after close some older Untitled file, it will use the number which is closed just now like vscode.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[msujew]

@yiliang114 Thank you for your first contribution!

I believe we can greatly simplify this change and cut down on the logic duplication. See below on how we could accomplish this.

[yiliang114]

What did I ignore caused two CI run failed? I try to find errors in log, get nothing useful but large empty section below limited content.

[msujew]

The code looks good already, however the changes to the plugin host code crash the runtime. See below for how to address this.

[msujew]

Thank you for your contribution, the changes look good to me 👍