Fix for XcURL and cURL behavior differences. (#733)

* Add Linux build files and configure files to support LibHttpClient Linux

* resolving comments

Removed extern structs in .h file and moved them up where they were in pch_common to ensure they are defined properly

* added templates

* Update x509_cert_utilities.hpp

* Update x509_cert_utilities.hpp

change check to something defined by us

* Update x509_cert_utilities.hpp

fix error in pipeline where there are errors of an unused function.

* Update x509_cert_utilities.hpp

use elif and corrected to use else

* Update CurlEasyRequest.cpp

Fix to handle behavioral differences with cURL and XcURL

* Update CurlEasyRequest.cpp

have this be a fix/workaround for xCurl

---------

Co-authored-by: SebastianPD-XB <sebastianp@microsoft.com>

Source/HTTP/Curl/CurlEasyRequest.cpp

@@ -41,14 +41,27 @@ Result<HC_UNIQUE_PTR<CurlEasyRequest>> CurlEasyRequest::Initialize(HCCallHandle
 
     // we set both POSTFIELDSIZE and INFILESIZE because curl uses one or the
     // other depending on method
-    // We are allowing Setops to happen with a bodySize of zero to handle certain clients
+    // We are allowing Setops to happen with a bodySize of zero in linux to handle certain clients
     // not being able to handle handshakes without a fixed body size.
+    // The reason for an if def statement is to handle the behavioral differences in libCurl vs xCurl.
+    
+    #if HC_PLATFORM == HC_PLATFORM_GDK
+        if (bodySize > 0) {
             RETURN_IF_FAILED(easyRequest->SetOpt<long>(CURLOPT_POSTFIELDSIZE, static_cast<long>(bodySize)));
             RETURN_IF_FAILED(easyRequest->SetOpt<long>(CURLOPT_INFILESIZE, static_cast<long>(bodySize)));
 
             // read callback
             RETURN_IF_FAILED(easyRequest->SetOpt<curl_read_callback>(CURLOPT_READFUNCTION, &ReadCallback));
             RETURN_IF_FAILED(easyRequest->SetOpt<void*>(CURLOPT_READDATA, easyRequest.get()));
+        }
+    #else
+        RETURN_IF_FAILED(easyRequest->SetOpt<long>(CURLOPT_POSTFIELDSIZE, static_cast<long>(bodySize)));
+        RETURN_IF_FAILED(easyRequest->SetOpt<long>(CURLOPT_INFILESIZE, static_cast<long>(bodySize)));
+
+        // read callback
+        RETURN_IF_FAILED(easyRequest->SetOpt<curl_read_callback>(CURLOPT_READFUNCTION, &ReadCallback));
+        RETURN_IF_FAILED(easyRequest->SetOpt<void*>(CURLOPT_READDATA, easyRequest.get()));
+    #endif
 
     // url & method
     char const* url = nullptr;