Bugfix/validate-user-provided-file-object-paths (#1197)

* Fixed BACnet file object path name unintended path traversals by optionally restricting path name content with BACNET_FILE_PATH_RESTRICTED define.

* Added POSIX file path name checking for AtomicReadFile and AtomicWriteFile example applications. Prohibits use of relative and absolute file paths when BACNET_FILE_PATH_RESTRICTED is non-zero.

test/bacnet/basic/object/netport/CMakeLists.txt

@@ -85,6 +85,7 @@ add_executable(${PROJECT_NAME}
     ${SRC_DIR}/bacnet/basic/sys/debug.c
     ${SRC_DIR}/bacnet/basic/sys/bigend.c
     ${SRC_DIR}/bacnet/basic/sys/days.c
+    ${SRC_DIR}/bacnet/basic/sys/filename.c
     ${SRC_DIR}/bacnet/basic/sys/keylist.c
     ${SRC_DIR}/bacnet/datalink/bvlc.c
     ${SRC_DIR}/bacnet/datalink/bvlc6.c