C++: Add change note

cpp/ql/src/change-notes/2024-03-22-boost-ssl.md

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+---
+category: queryMetadata
+---
+* `@precision medium` metadata was added to the `cpp/boost/tls-settings-misconfiguration` and `cpp/boost/use-of-deprecated-hardcoded-security-protocol` queries, and these queries are now included in the security-extended suite. The `@name` metadata of these queries were also updated.