Enable deleting issue platform issues from the issues stream

I believe I already finished the backend work (see [test](https://github.com/getsentry/sentry/blob/4751ac2ba43d0f66af9323c60809108fa8aefe87/tests/snuba/api/endpoints/test_project_group_index.py#L1619-L1639)). Add a bulk delete test mixing both error issues and issue platform issues. I want to see if we need to change the code handling [the countdown value](https://github.com/getsentry/sentry/blob/4909326e293b1aebc6f69c4d3dc5404b66f7dfd7/src/sentry/api/helpers/group_index/delete.py#L56-L59). You will need to find the UI code that controls deleting issues from the issue stream and change it. <img width="696" alt="Image" src="https://github.com/user-attachments/assets/428b928a-6028-4b24-a1e1-836ebf9a06a5" />