PEARL: Sorensen issues

[rerpha]

As a PEARL instrument scientist I have some issues with the sorensen hi-pt PSU.

• When i use a furnace and set a current, the power ramps then stops and resets everything
• When i send a stop things are sent immediately so may get missed (without warning as the sets have no IN statement in the .proto)

Acceptance criteria

• [ ] These issues are fixed

[rerpha]

https://github.com/ISISComputingGroup/EPICS-Dhp30330/pull/5 https://github.com/ISISComputingGroup/IBEX/pull/8183

This has been tested on PEARL and scientist is happy, so to review just check the changes make sense.