We changed the test query when the query was changed so that the
comments in the test file would stay the same.
I've reverted the test query and updated the comments in the test file.
This avoids problems in the branch switching to use-use flow.
This was amended as part of https://github.com/github/codeql/pull/12186, but the conversion was inadequate because the new implementation didn't work when a sink (type conversion) led directly to a non-`localTaintStep` step, such as a store step or an interprocedural step. Here I move the sink back one step to the argument of the type
conversion and sanitize the result of the conversion instead, to ensure there is always a unique local successor to a sink.
This should eliminate unexpected extra results that resulted from https://github.com/github/codeql/pull/12186. Independently there are also *lost* results that stem from needing a higher `fieldFlowBranchLimit` that are not addressed in this PR, but raising that limit is a performance risk and so I will address this separately.
