updateDropZoneInput: Change the values or settings of a dropzone on the client
In serenity-r/dragulaSelectR: Implements a drag-and-drop Shiny select input

The set of presets can be cleared by using presets=character(0).

updateDropZoneInput(
  session = getDefaultReactiveDomain(),
  inputId,
  presets = NULL,
  choices = NULL,
  placeholder = NULL
)

`session`	The session object passed to function given to shinyServer.
`inputId`	The `input` slot that will be used to acces the value.
`presets`	Array or list of preset values.
`choices`	List of acceptable values with their associated labels. Note that the labels can be arbitrary HTML, as long as they are wrapped in a `tagList`.
`placeholder`	Insert placeholder text.