[Activity Tab] Note which of the linked Issues caused the Jira Issue state to change when multiple links

### Problem Statement

Related to: https://github.com/getsentry/sentry/issues/62565

Related to: https://sentry.zendesk.com/agent/tickets/145274

When I link more than one Sentry Issue to an external Jira Issue a regression in one will cause the other linked Sentry issues to re-open under certain circumstances. Work was done to make it clear why the issue was being marked as unresolved (because of Jira) but does not sufficiently answer the underlying question of WHY the Jira issue is marking the linked issues as unresolved.

### Solution Brainstorm

Consider adding (due to regression in ) to "Sentry marked this issue as unresolved via Jira"

As noted in #62565 some environments make it challenging to self-serve the information needed to make sense of these automatic Sentry issue state changes.

For both #62565 and https://sentry.zendesk.com/agent/tickets/145274 a query was run against the database to find the other Sentry issue linked to the external issue

### Product Area

Issues

Start with the Activity Tab Jira state-change flow and the related issue #62565, since no source files or tests are named here. Trace how multiple Sentry Issues linked to one Jira Issue are represented and how the unresolved message is generated. Done means the activity explains which linked Sentry Issue caused the Jira-driven state change, with coverage for multiple links.

Written by the indexing model from the issue text.