This removes all uses of `Declaration.getQualifiedName` that I think can
be removed without changing any behaviour. The following uses in the
LGTM default suite remain:
* `cpp/ql/src/Security/CWE/CWE-121/UnterminatedVarargsCall.ql` (in `select`).
* `cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowDispatch.qll` (needs template args).
* `cpp/ql/src/semmle/code/cpp/security/FunctionWithWrappers.qll` (used for alert messages).