Added recipes for curl (libcurl-static)

[anutosh491]

We can have 3 outputs here (curl, libcurl and libcurl-static). I guess we would not need the first two.

[anutosh491]

Need to

1. Add tests
2. look into the required configuration flags (a couple might be unncessary)
3. Not all file maybe necessary, so I guess we can select the ones we want.

[anutosh491]

I did this for supporting magics in xeus-cpp but thinking about it, having libcurl would help us compile the RCurl R package (cc @IsabelParedes might be interested here)

[DerThorsten]

curl will very likely not work in the browser (tempted to close this PR)

[anutosh491]

curl will very likely not work in the browser (tempted to close this PR)

I had my doubts but then I saw curl being used in wasm at few resources

1. https://curl.se/download.html (its through wasix, so search for wasix)
2. https://github.com/wapm-packages/curl
3. Duplicate symbols when compiling for wasm with emscripten curl/curl#13018 (comment)

And the xeus-cpp use case was just blocked since a while so I thought of raising it and this recipe is only for libcurl-static (not for the other 2 components which are curl and libcurl). Let me know what you think.

[DerThorsten]

curl will very likely not work in the browser (tempted to close this PR)

I had my doubts but then I saw curl being used in wasm at few resources

1. https://curl.se/download.html (its through wasix, so search for wasix)
2. https://github.com/wapm-packages/curl
3. Duplicate symbols when compiling for wasm with emscripten curl/curl#13018 (comment)

And the xeus-cpp use case was just blocked since a while so I thought of raising it and this recipe is only for libcurl-static (not for the other 2 components which are curl and libcurl). Let me know what you think.

So while compiling curl is possible I doubt that anything meaningful will work for the browser.
This can work for wasi / wasix or other platforms when they emulate the appropriate syscalls, but in the browser you will need to use async APIs for downloading things (ie the fetch API ).
If there is no dedicated code in the curl codebase to handle emscripten, this will not work to download things

[anutosh491]

Thanks for the explanation here @tharun571 why exactly do we use curl in xeus-cpp. Cause I guess the above confirms we might not be able to use it.

[tharun571]

@anutosh491 I am using curl to call the LLMs in xeus-cpp. As mentioned above, fetch API might be something I will try for our project.

[anutosh491]

Closing as won't work.