Add a way to request new minidumps for a specific issue

### Problem Statement

Often we will find that a crash will have a very old and hard to work with minidump if the crash has been around but unsolved for a long time. With a limit set on number of minidumps per issue, I can delete an old minidump to let sentry store a new one but it can be useful to keep old ones around for comparison's sake. As such, I'd like to propose a button that lets you bump up the minidump limit just for one specific issue, potentially with a notification once a new one is captured.

### Solution Brainstorm

_No response_

### Product Area

Issues

No files, tests, or entry points are named; start by reading the minidump-limit and notification proposal in the Issues product area. Clarify the per-issue limit and notification behavior with maintainers before implementation, then verify that new minidumps can be retained for comparison without changing other issues.

Written by the indexing model from the issue text.