sysutils/fusefs-unreliablefs: Add new port

UnreliableFS is a FUSE-based fault injection filesystem that allows to
change fault-injections in runtime using simple configuration file.

Supported fault injections are:
- errinj_errno - return error value and set random errno.
- errinj_kill_caller - send SIGKILL to a process that invoked file
  operation.
- errinj_noop - replace file operation with no operation (similar to
  libeatmydata, but applicable to any file operation).
- errinj_slowdown - slowdown invoked file operation.

WWW: https://github.com/ligurio/unreliablefs