Remove the remains of query categories
Back in October 2020 in #77830 ``@cjgillot`` removed the query categories information from the profiler, but the actual definitions which query was in which category remained, although unused.
Here I clean that up, to simplify the query definitions even further.
It's unfortunate that this loses all the context for `git blame`, ~~but I'm working on moving those query definitions into `rustc_query_system`, which will lose that context anyway.~~ EDIT: Might not work out.
The functional changes are in the first commit. The second one only changes the indentation.
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