JUNGFRAU: condition watcher to look for new firmware key names

It's been on the horizon for a while https://git.xfel.eu/calibration/planning/-/issues/143 and AFAICT, the JF4M@SPB has the new keys rather than the old, so it's about time the condition watcher is aware. To avoid assuming all installations will have already been updated, the device can handle "old" or "new" firmware version - I figure we can come up with more descriptive naming if we one day have more than two options.

Also, I removed the rounding after finding https://redmine.xfel.eu/issues/143783 that rounding is sometimes too much. Technically, there is no reason why the condition watcher would need to round - constants should be injected with appropriate deviations, so querying for a bias voltage of 349.9999875202775 should work fine. The only downside of not rounding something like bias voltage would be if you set automatic mode with automatically re-querying of constants and the value fluctuates a lot.

Anyway, does the "new" firmware case handling look appropriate? @ahmedk @mramilli

Bonus: I hotpatched the SPB installation and it looks like SPB_IRDA_JF4M/CAL/CONDITION is happy: