Add https binary cache

[autoantwort]

This can be used to use gitlab generic packages as binary cache.

We could also allow http.

Maybe we should replace the header field by 'options to curl'. Then the -u option or multiple headers could be used.

[Osyotr]

http support can be useful when pushing/fetching from internal server

[BillyONeal]

Thanks!

[BillyONeal]

This completely broke binary caching for x-azblob because it causes curl command lines like:

curl --create-dirs --location -w "5ec47b8e-6776-4d70-b9b3-ac2a57bc0a1c %{http_code}\n" "https://vcpkgbinarycacheeastasia.blob.core.windows.net/cache/06db868bb3ae7a8a4d85685d799e0630d91a4594b9c1caa6dac361a42a46c407.zip?SAS" -o "C:\Dev\vcpkg\buildtrees\vcpkg-cmake\x64-windows.zip" -H "x-ms-version: 2020-04-08" -H "x-ms-blob-type: BlockBlob" "https://vcpkgbinarycacheeastasia.blob.core.windows.net/cache/dcc66cf2da4a2a8f4526bd8f779c455afb9eca970749bd0a123f8f1152b18630.zip?SAS" -o "C:\Dev\vcpkg\buildtrees\zlib\x86-windows.zip" -H "x-ms-version: 2020-04-08" -H "x-ms-blob-type: BlockBlob"

Note that -H is duplicated. https://curl.se/docs/manpage.html#-H -H is sent for all requests, not per-url like this appears to be trying to do.

[BillyONeal]

[autoantwort]

This are actually two issues:

1. Headers are send twice
2. azure blob headers meant for put requests are also send in get requests (I didn't know that and thought it would be ok to also send them in get requests)

I have fixed this two issues in #592