Improvements and fixes

Whether a device is online is now answered the same on every page, instead of differently on each.

• A stopped on-site agent no longer shows green for fifteen minutes, a short restart gap shows amber, and a device never seen shows grey.
• Battery converters and containers now show the state they report about themselves, for NR Electric converters and Linyang containers.
• The AC/DC switch beside a converter's graph now works, and a separate DC entry in the list of values is no longer needed.
• The visibility and shared note of several ticked combiner boxes can now be changed in one go, per inverter, data logger or whole plant.
• The assistant can now hide the components on one data logger, showing what would change and applying it only after confirmation.