Warn before applying issue template
What does this MR do?
Adds a content override warning when applying another template.
Does this MR meet the acceptance criteria?
Conformity
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Changelog entry for user-facing changes, or community contribution. Check the link for other scenarios. -
Documentation created/updated or follow-up review issue created -
Code review guidelines -
Merge request performance guidelines -
Style guides -
Database guides -
Separation of EE specific content
Closes #16188 (closed)