Added rules to disable start buttons when vacuum interlock bad

[davidkeymer]

Description of work

Add rules to appropriate buttons to control their enable properties based on interlock status PVs.

NB two OPIs edited - one each for analogue drive chopper (original) and digital drive (MAPS)

Ticket

see ticket

Acceptance criteria

See ticket

Unit tests

None

System tests

N/A

Documentation

Line in release notes

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Code Review

• Is the code of an acceptable quality?
• If the change is to an OPI, does the check_opi_format.py script in C:\Instrument\Dev\ibex_gui\base\uk.ac.stfc.isis.ibex.opis pass?
• Do the changes function as described and is it robust?
• Is there associated PR for the release notes?

Final Steps

• Reviewer has also merged the release notes