Draft: Condition watcher improvements

Goals:

• condition watcher should robustly keep track of the devices it's supposed to be watching
• it should be very clear about errors
• (bonus) option to copy individual settings

Also included rounding for JUNGFRAU integration time. But maybe a better option is to let any given parameter comparison define what is close enough. That requires a bit more restructuring, but maybe we need that anyway to support parameters set not just by translating a single control value (ex. JUNGFRAU gain mode depending on gain mode but maybe also burst mode).