INTER - safety upgrades

[rerpha]

As an INTER scientists I would like to not lose all of my open loop axes' positions when power is cut to the drive cards due to a motion safety trip.

Acceptance criteria

• Variable is added to load in the "about to trip" signal from INTER's Beckhoff
• this is forwarded to abort all motion on all galil axes so we don't lose positions.

[rerpha]

https://github.com/ISISComputingGroup/ibex_developers_manual/wiki/INTER-Instrument-Details#note-motion-safety
ISISComputingGroup/EPICS-motorExtensions#71

there isn't really a nice way of testing on your machine, but we have tested on INTER and it's working.