Project manager should warn when two projects share the same groupId and artifactId

Is your feature request related to a problem? Please describe.

I have a workspace of multiple Java projects. When two projects share the same groupId and artifactId, one of them do not get recognized by Project Manager, and thus not able to get built and debugged.

Describe the solution you'd like

In the case, project manager should either support it or throw error about it, instead of silently doing nothing.

Describe alternatives you've considered

I have to remove one of the projects from the same workspace to get the other loading.

Additional context
Add any other context or screenshots about the feature request here.

まず、プロジェクトを groupId と artifactId で識別する vscode-java リポジトリ内の Project Manager のロジックを特定し、次に、同じ workspace 内で両方の値を共有する 2 つの Java プロジェクトを使って問題を再現します。完了の条件は、プロジェクトが一緒にサポートされるか、Project Manager が一方を黙って無視するのではなく、明示的なエラーを提示することです。