PV sets: bulk update config

[Tom-Willemsen]

As a scientist on HIFI with lots of parameters in PV sets in the ZFHIFI ioc, I would like an easier method to update many PV sets in my config all at once.

Some way to "save" the current, manually set, values into the PV sets in the config was requested.

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Alternatively make ZFHIFI autosave these numbers instead of having them in pv sets in config - but I felt it was nicer to have them in the config as easier to track when they changed in version control etc.

[KathrynBaker]

Would implementing #8161 be an option to resolve this?