debug: add a 'debugdownload' command
This command resolve and fetch and URL through the Mercurial logic. Mercurial
logic add various headers (including authentication) while resolving an URL so
the commands helps with building the same request Mercurial would be doing.
A new test file is created because we'll add more logic regarding Mercurial
download logic and it will grow to a reasonable size.
# Files that just need to be migrated to the formatter.
# Do not add new files here!
contrib/chg/chg.c
contrib/chg/hgclient.c
contrib/chg/hgclient.h
contrib/chg/procutil.c
contrib/chg/procutil.h
contrib/chg/util.c
contrib/chg/util.h
contrib/hgsh/hgsh.c
mercurial/cext/base85.c
mercurial/cext/bdiff.c
mercurial/cext/charencode.c
mercurial/cext/charencode.h
mercurial/cext/diffhelpers.c
mercurial/cext/dirs.c
mercurial/cext/manifest.c
mercurial/cext/mpatch.c
mercurial/cext/osutil.c
mercurial/cext/pathencode.c
mercurial/cext/revlog.c
# Vendored code that we should never format:
contrib/python-zstandard/c-ext/bufferutil.c
contrib/python-zstandard/c-ext/compressiondict.c
contrib/python-zstandard/c-ext/compressionparams.c
contrib/python-zstandard/c-ext/compressionwriter.c
contrib/python-zstandard/c-ext/compressobj.c
contrib/python-zstandard/c-ext/compressor.c
contrib/python-zstandard/c-ext/compressoriterator.c
contrib/python-zstandard/c-ext/constants.c
contrib/python-zstandard/c-ext/decompressionwriter.c
contrib/python-zstandard/c-ext/decompressobj.c
contrib/python-zstandard/c-ext/decompressor.c
contrib/python-zstandard/c-ext/decompressoriterator.c
contrib/python-zstandard/c-ext/frameparams.c
contrib/python-zstandard/c-ext/python-zstandard.h
contrib/python-zstandard/zstd.c
contrib/python-zstandard/zstd/common/bitstream.h
contrib/python-zstandard/zstd/common/entropy_common.c
contrib/python-zstandard/zstd/common/error_private.c
contrib/python-zstandard/zstd/common/error_private.h
contrib/python-zstandard/zstd/common/fse.h
contrib/python-zstandard/zstd/common/fse_decompress.c
contrib/python-zstandard/zstd/common/huf.h
contrib/python-zstandard/zstd/common/mem.h
contrib/python-zstandard/zstd/common/pool.c
contrib/python-zstandard/zstd/common/pool.h
contrib/python-zstandard/zstd/common/threading.c
contrib/python-zstandard/zstd/common/threading.h
contrib/python-zstandard/zstd/common/xxhash.c
contrib/python-zstandard/zstd/common/xxhash.h
contrib/python-zstandard/zstd/common/zstd_common.c
contrib/python-zstandard/zstd/common/zstd_errors.h
contrib/python-zstandard/zstd/common/zstd_internal.h
contrib/python-zstandard/zstd/compress/fse_compress.c
contrib/python-zstandard/zstd/compress/huf_compress.c
contrib/python-zstandard/zstd/compress/zstd_compress.c
contrib/python-zstandard/zstd/compress/zstd_opt.h
contrib/python-zstandard/zstd/compress/zstdmt_compress.c
contrib/python-zstandard/zstd/compress/zstdmt_compress.h
contrib/python-zstandard/zstd/decompress/huf_decompress.c
contrib/python-zstandard/zstd/decompress/zstd_decompress.c
contrib/python-zstandard/zstd/dictBuilder/cover.c
contrib/python-zstandard/zstd/dictBuilder/divsufsort.c
contrib/python-zstandard/zstd/dictBuilder/divsufsort.h
contrib/python-zstandard/zstd/dictBuilder/zdict.c
contrib/python-zstandard/zstd/dictBuilder/zdict.h
contrib/python-zstandard/zstd/zstd.h
hgext/fsmonitor/pywatchman/bser.c