build: various build fixes ( libxml2 > 2.9.10 ), gcp provider after new logging...

various build fixes

• libxml2 > 2.9.10 support
• gcp provider after new logging changes
• gcp storage test with ibm provider turned on

docker images not yet updated accordingly.

tested build with the following updates:

{
 "openssl": { "version" : "1.1.1g", "url" : "https://www.openssl.org/" },
 "libxml2": { "version" : "2.9.10", "url" : "https://github.com/GNOME/libxml2" },
 "azure_sdk_for_cpp": { "version" : "12.0.0", "url" : "https://github.com/Azure/azure-sdk-for-cpp" }
}

to

{
 "openssl": { "version" : "1.1.1l", "url" : "https://www.openssl.org/" },
 "libxml2": { "version" : "2.9.12", "url" : "https://github.com/GNOME/libxml2" },
 "azure_sdk_for_cpp": { "version" : "12.1.0", "url" : "https://github.com/Azure/azure-sdk-for-cpp" }
}