Consume page: Add to solution experience

**System Information (please complete the following information):**
- Model Builder Version (available in Manage Extensions dialog):
- Visual Studio Version

**Describe the bug**
- On which step of the process did you run into an issue: Consume page
- Clear description of the problem:
If a project template by any name "xyz" has been added to the solution, and if I try to "Add again" the same template with the same name "xyz", it shows a dialog that "project with the same name already exists".
If I hit "no" on this warning dialog, another dialog pops up saying this..


**To Reproduce**
Steps to reproduce the behavior:
1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

**Expected behavior**
If the customer hits "No" on the "Overwrite project dialog", it should simply close the "overwrite" dialog and bring the customer back to the original "Add to solution" dialog with a focus on the text in the name field.
As shown in these mock-ups here...

https://www.figma.com/file/bhdPADawiO4YQGdUNExiUc/All-Scenarios?node-id=32%3A20372


**Screenshots**
If applicable, add screenshots to help explain your problem.

**Additional context**
Add any other context about the problem here.

Consume ページの Add to solution フローから開始し、"xyz" という名前のプロジェクトテンプレートを 2 回追加する操作を再現します。上書き警告と後続のダイアログを調べ、その後、リンクされた Figma モックアップと操作を比較します。No を選択すると上書きダイアログが閉じ、Add to solution に戻り、名前フィールドにフォーカスが移ることが完了の条件です。

索引モデルが issue の本文から書いたものです。