Jaws manager and other OPIs: performance

[Tom-Willemsen]

As a user/scientist using the jaws manager screen, I would like the jaws manager OPI to open quickly.

Seen when migrating NIMROD's jaws: clicking the "jaws manager..." button from the jaws overview panel takes approx 25s on NIMROD before the OPI opens and the GUI is unresponsive during this time. This is compared to ~2s for opening the motor details panel from the motor overview panel (which opens by a similar mechanism and has a similar number of PVs, many of which update quickly).

See if the performance of this OPI can be increased so that it is comparable to other OPIs, e.g. by putting scripts on another thread or reducing the complexity of the scripts.

[Tom-Willemsen]

Timebox to 2 days, then remove the scripts if you don't get anywhere

[John-Holt-Tessella]

We made a change for caen because of a change made in cs studio see #4350, this can also be a more specific case of #4428

[Tom-Willemsen]

PR at ISISComputingGroup/ibex_gui#959

Note: this only makes scripts faster. There is still an issue at #4428 for speeding up the rest of the OPI rendering process (e.g. the very first OPI being slow to open)