fbcode_builder: rename add_thrift_cpp2_library() to add_fbthrift_cpp_library()

Summary:
Rename the `ThriftCppLibrary.cmake` file to `FBThriftCppLibrary.cmake`, and
also rename `add_thrift_cpp2_library()` to `add_fbthrift_cpp_library()`.

Explicitly calling this `fbthrift` helps clearly distinguish that this is
intended for use with fbthrift (https://github.com/facebook/fbthrift/), as
opposed to Apache thrift.

Reviewed By: wez

Differential Revision: D16738440

fbshipit-source-id: 9b255e06b71c98ad74a34989f564a211958dcdd5

Author: simpkins

build/fbcode_builder/CMake/ThriftCppLibrary.cmake renamed to build/fbcode_builder/CMake/FBThriftCppLibrary.cmake

@@ -20,7 +20,7 @@ include(FBCMakeParseArgs)
 #   Defaults to "${INCLUDE_DIR}/thrift-files" if not specified.
 #   The caller must still call install() to install the thrift library if
 #   desired.
-function(add_thrift_cpp2_library LIB_NAME THRIFT_FILE)
+function(add_fbthrift_cpp_library LIB_NAME THRIFT_FILE)
   # Parse the arguments
   set(one_value_args INCLUDE_DIR)
   set(multi_value_args SERVICES DEPENDS OPTIONS THRIFT_INCLUDE_DIR)
@@ -93,7 +93,7 @@ function(add_thrift_cpp2_library LIB_NAME THRIFT_FILE)
   # include list as a single argument and split it up before invoking the
   # thrift compiler.
   if (NOT POLICY CMP0067)
-    message(FATAL_ERROR "add_thrift_cpp2_library() requires CMake 3.8+")
+    message(FATAL_ERROR "add_fbthrift_cpp_library() requires CMake 3.8+")
   endif()
   set(
     thrift_include_options