Application and RouDi lock files are not removed after termination

[elfenpiff]

Required information

When an application or roudi is starting a lock file is created, e.g. /tmp/iox-unique-roudi.lock. When running applications/roudi as different users or in a docker environment and the lock file remains there the applications are unable to acquire the file lock.

This ends up in the error message:

iceoryx/iceoryx_hoofs/source/posix_wrapper/file_lock.cpp:51 { iox::cxx::expected<iox::posix::FileLockError> iox::posix::FileLock::initializeFileLock() -> iox_open }  :::  [ 13 ]  Permission denied
permission to access file denied "roudi"
2022-03-03 11:49:21.858 [ Fatal ]: Error occurred while acquiring file lock named roudi
2022-03-03 11:49:21.858 [ Error ]: ICEORYX error! IPC_INTERFACE__COULD_NOT_ACQUIRE_FILE_LOCK

To solve this the FileLock posix wrapper, which creates the file in the first place in the constructor, has to also remove the file in the destructor.

Currently the file lock only closes the file descriptor but never unlocks it!