TPG300 - set alarm limits dynamically based on if vacuum is good/bad

[isaachilly]

As a developer make a PV (e.g., TPG300:PressureAlarmControl) that fans out to the limits of the pressure PVs A2 and B2 a normal range or a very large range based on if the vacuum is good so as to not raise an alarm when vacuum is fine.

Acceptance Criteria

• James Lord said what constitutes a "good vacuum' changes so he'd like just a macro in the IOC to set whether the pressure alarms A2 and B2 alarm or not. I.E pressure_alm_when_vacuum = "ALARM/NO_ALARM".
• PV created that sets the alarm limits of the pressure PVs to have a large range if vacuum is good so that the alarm is not called and a normal range if vacuum is bad.

Extra Information

Umbrella ticket:

• Alarms: Refinements for use #8189

How to Test

verbose instructions for reviewer to test changes
(Add before making a PR)
time in planning 00:38 23/5/24

[isaachilly]

Comments: After speaking with Freddie we decided to create 2 macros one for channel 1 and one for channel 2. How scientists use alarms and how they COULD use them gets too complicated to foresee and so if this needs adapting/building upon etc then we said so be it, we can only do what we can now.