quick commands cause error if device tree not known yet

[sebkopf]

For devices that are new, sending one of the quick commands causes an error because it's trying to edit a structure that is not known yet - catch this problem with a warning to "Request latest data" first

Trace (do NOT delete)

<error/rlang_error>
Error in `UseMethod()`:
! no applicable method for 'filter' applied to an object of class "NULL"
---
Backtrace:
    ▆
 1. ├─shiny (local) `<observer:observeEvent(input$zero)>`(...)
 2. │ └─micrologger (local) observe()
 3. │   └─sdds$edit_structure("sensor.action", value = "zero")
 4. │     └─sddsParticle:::get_structures_for_path_in_app(...)
 5. │       └─dplyr::filter(structures, .data$path == !!path)
 6. └─base::.handleSimpleError(...)
 7.   └─sddsParticle (local) h(simpleError(msg, call))