Set cmake var proxygen_LIBRARIES so other dependencies like MOQ can access those libs

Summary: - Publish the CMake var `proxygen_LIBRARIES` so other dependencies like MOQ can access those libs in a clean way

Reviewed By: lnicco

Differential Revision: D56689826

fbshipit-source-id: ee456f8f0c1d730e1bf2a53c89f0a1bfb6891570

Author: jordicenzano

cmake/proxygen-config.cmake.in

@@ -50,3 +50,12 @@ endif()
 if(NOT proxygen_FIND_QUIETLY)
     message(STATUS "Found proxygen: ${PACKAGE_PREFIX_DIR}")
 endif()
+
+set(proxygen_LIBRARIES
+  proxygen::proxygen
+  proxygen::proxygencurl
+  proxygen::proxygendeviousbaton
+  proxygen::proxygenhqloggerhelper
+  proxygen::proxygenhttpserver
+  proxygen::proxygenhqserver
+)