This commit rewrites all of the tidy checks we have, namely:
* featureck
* errorck
* tidy
* binaries
into Rust under a new `tidy` tool inside of the `src/tools` directory. This at
the same time deletes all the corresponding Python tidy checks so we can be sure
to only have one source of truth for all the tidy checks.
cc #31590
associated machinery. Future such attempts should go through lints
anyhow.
There is a fair amount of fallout in the compile-fail tests, as WF
checking now occurs earlier in the process.
