POLREF: HTS Magnet controller Current precision

# Issue Description
As a user, I am would like the HTS 110K magnet on POLREF controller to handle current setpoints to 2 decimal places e.g. 14.46 Amps rather than what it currently does which is 14A for that value. It seems that the VI does take the decimal places and set the controller to them but rounds up or down the setpoint display box.

### How & Where?
- Support email from Christy Kinane on POLREF
- Possibly somewhere in the EPICS support module.

# Acceptance Criteria
_{What is the acceptance criteria of this ticket? What should the reviewer expect to be complete?}
- Magnet current setpoints can be set to at least 2 decimal places and the current readback also.

# How to Review
_{Before making a PR...}
- The VI can set currents to 2 DP and readback similarly.
- Tests added to validate.