SectorReader::ReadChunk does do some validation on it, but it only
checks against the original disc size (reported by the GCZ file).
It has no idea how many blocks the header claimed the disc had.

A maliciously crafted GCZ file could trigger read overflows off the end
of the m_block_pointers/m_hashes arrays.

It comes unverified from the file, and a maliciously crafted file could
trigger not one, but two buffer overflows in the heap.

Accomplished using `run-clang-tidy` with `performance-move-const-arg,performance-unnecessary-value-param,modernize-pass-by-value`.

Changed arguments to const references, removed them where inappropriate (e.g. sink parameters). Same with std::move.

Manually reviewed each change to make sure that it makes sense, and do something more appropriate if possible.

Yellow squiggly lines begone!
Done automatically on .cpp files through `run-clang-tidy`, with manual corrections to the mistakes.
If an import is directly used, but is technically unnecessary since it's recursively imported by something else, it is *not* removed.
The tool doesn't touch .h files, so I did some of them by hand while fixing errors due to old recursive imports.
Not everything is removed, but the cleanup should be substantial enough.
Because this done on Linux, code that isn't used on it is mostly untouched.
(Hopefully no open PR is depending on these imports...)

DiscIO: Pass parameters by constant reference