Full Param List/Tree: handle both values and ranges for a single parameter

There are some parameters that have both ranges and values defined (e.g. ACRO_RP_EXPO) and it would be nice if MP's parameter list and tree views allows either to be used similar to how the checkboxes work for ARMING_CHECK. So perhaps pop-up a drop-down list if the parameter has values but also allow the user to directly enter the number.

related flight code PR: https://github.com/ArduPilot/ardupilot/pull/17568

Start with Mission Planner's parameter list and tree views, using ACRO_RP_EXPO and ARMING_CHECK as the examples described in the issue; review the related flight-code PR for context. Done means parameters with both values and ranges offer selectable values while still accepting direct numeric entry in both views.

Written by the indexing model from the issue text.