Revert back to Argon2 reference library

* Fix #7487 - Botan does not use threads when calculating Argon2 KDF leading to very poor performance for a parallelism value > 1.
* Include port file for vcpkg backed builds

utils/vcpkg_ports/argon2/portfile.cmake

@@ -0,0 +1,25 @@
+vcpkg_check_linkage(ONLY_STATIC_LIBRARY)
+
+vcpkg_from_github(
+    OUT_SOURCE_PATH SOURCE_PATH
+    REPO P-H-C/phc-winner-argon2
+    REF 20190702
+    SHA512 0a4cb89e8e63399f7df069e2862ccd05308b7652bf4ab74372842f66bcc60776399e0eaf979a7b7e31436b5e6913fe5b0a6949549d8c82ebd06e0629b106e85f    
+    HEAD_REF master
+)
+
+configure_file(${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt ${SOURCE_PATH}/CMakeLists.txt COPYONLY)
+
+vcpkg_configure_cmake(
+    SOURCE_PATH ${SOURCE_PATH}
+    PREFER_NINJA
+    OPTIONS
+        ${FEATURE_OPTIONS}
+    OPTIONS_DEBUG
+        -DDISABLE_INSTALL_HEADERS=ON
+)
+
+vcpkg_install_cmake()
+vcpkg_copy_pdbs()
+
+file(INSTALL ${SOURCE_PATH}/LICENSE DESTINATION ${CURRENT_PACKAGES_DIR}/share/${PORT} RENAME copyright)